Disabled Google Tests that we don't have to deal.

Loads of additions.
-Added: Indirect Sorters. -Added: ReferenceMaps -Fixed: A bunch of smaller bugs found due to tests
2026-05-14 21:32:16 +02:00 · 2026-05-14 19:21:38 +02:00 · 2026-05-14 02:51:38 +02:00 · 2026-05-12 13:37:22 +02:00 · 2026-05-11 18:00:00 +02:00 · 2026-05-11 00:36:08 +02:00
105 changed files with 8310 additions and 1252 deletions
@@ -6,12 +6,6 @@
 			<attribute name="gradle_used_by_scope" value="main,test"/>
 		</attributes>
 	</classpathentry>
-	<classpathentry kind="src" output="bin/main" path="src/main/resources">
-		<attributes>
-			<attribute name="gradle_scope" value="main"/>
-			<attribute name="gradle_used_by_scope" value="main,test"/>
-		</attributes>
-	</classpathentry>
 	<classpathentry kind="src" output="bin/test" path="src/test/java">
 		<attributes>
 			<attribute name="gradle_scope" value="test"/>
@@ -11,20 +11,20 @@ jobs:
      strategy:
         fail-fast: false
         matrix:
-            jdk: [8, 11, 16, 17, 18, 19, 20]
+            jdk: [8, 11, 17, 20, 21]

      runs-on: ubuntu-latest
      steps:
-         - uses: actions/checkout@v3
+         - uses: actions/checkout@v6
         
         - name: Set up JDK ${{ matrix.jdk }}
-           uses: actions/setup-java@v3
+           uses: actions/setup-java@v5
           with:
               distribution: 'temurin'
               java-version: ${{ matrix.jdk }}

         - name: Validate Gradle wrapper
-           uses: gradle/wrapper-validation-action@v1
+           uses: gradle/actions/wrapper-validation@v6

         - name: Make gradlew executable
           run: chmod +x ./gradlew
@@ -9,12 +9,12 @@ jobs:
      name: Unit Tests
      runs-on: ubuntu-latest
      steps:
-      -  uses: actions/checkout@v3
+      -  uses: actions/checkout@v6
         with:
            fetch-depth: 0
            
      -  name: Set up JDK 11
-         uses: actions/setup-java@v3
+         uses: actions/setup-java@v5
         with:
            distribution: temurin
            java-version: 11
@@ -54,7 +54,7 @@ jobs:
            esac

      -  name: Create Test Badge
-         uses: emibcn/badge-action@v1.2.4
+         uses: emibcn/badge-action@v2
         with:
            label: Tests
            status: '${{ fromJSON( steps.test-results.outputs.json ).conclusion }}, Passed: ${{ fromJSON( steps.test-results.outputs.json ).formatted.stats.tests_succ }}, Skipped: ${{ fromJSON( steps.test-results.outputs.json ).formatted.stats.tests_skip }}, Failed: ${{ fromJSON( steps.test-results.outputs.json ).formatted.stats.tests_fail }}'
@@ -8,11 +8,11 @@ jobs:
    name: Code Quality Check
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
        with:
          fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
      - name: Set up JDK 11
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v5
        with:
          distribution: 'temurin'
          java-version: 11
@@ -9,12 +9,12 @@ jobs:
      name: Unit Tests
      runs-on: ubuntu-latest
      steps:
-      -  uses: actions/checkout@v2
+      -  uses: actions/checkout@v6
         with:
            fetch-depth: 0
            
      -  name: Set up JDK 11
-         uses: actions/setup-java@v3
+         uses: actions/setup-java@v5
         with:
            distribution: temurin
            java-version: 11
@@ -2,21 +2,22 @@
 <projectDescription>
 	<name>Primitive-Collections</name>
 	<comment></comment>
-	<projects/>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.eclipse.buildship.core.gradleprojectbuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
 	<natures>
 		<nature>org.eclipse.jdt.core.javanature</nature>
 		<nature>org.eclipse.buildship.core.gradleprojectnature</nature>
 	</natures>
-	<buildSpec>
-		<buildCommand>
-			<name>org.eclipse.jdt.core.javabuilder</name>
-			<arguments/>
-		</buildCommand>
-		<buildCommand>
-			<name>org.eclipse.buildship.core.gradleprojectbuilder</name>
-			<arguments/>
-		</buildCommand>
-	</buildSpec>
-	<linkedResources/>
-	<filteredResources/>
 </projectDescription>
@@ -1,5 +1,21 @@
 # Changelog of versions

+### Version 0.9.0
+- Added: getFirst/getLast/removeFirst/removeLast to List.class.
+- Added: Dedicated Set toArray implementations.
+- Added: ToArray/pushTop functions to Stack.class.
+- Added: ComputeNonDefault functions which will contain the current behavior of the Compute function, while the Compute will be changed to be more java compliant!
+- Added: List.reversed, which returns a SubList that has all elements in reversed order and also inserts reversed.
+- Added: Iterators.infinite as an option that will create a Infinite Iterator based on the inputed one.
+- Added: List.indexedIterator which allows you to create a iterator with a customized iteration indecies. Useful if you want to transform lists output.
+- Added: PriorityQueue.contains is now a function
+- Added: Iterators/Async Builders now support MapToPrimitiveType function on the object variant. So more processing can be done. (Will be expanded upon later versions)
+- Fixed: SetValue wasn't working on forEach implementations.
+- Fixed: Compute functions now perform with primitives more java compliant. Meaning that getDefaultReturnValue function no longer is seen as null.
+- Fixed: Supplier was using the wrong dataType in their function name.
+- Updated: SimpleCodeGenerator 1.3.0 is now being used which allows for iterative code support.
+- Breaking Change: Map.compute/IfAbsent/Present and Map.supplyIfAbsent if the value is a primitive it will no longer accept the defaultReturnValue() as "null" if that functionality is desired then use: computeNonDefault which contains the functionality!
+
 ### Version 0.8.1
 - Added: getFirst/getLast/removeFirst/removeLast to List.class.
 - Added: Dedicated Set toArray implementations.
@@ -30,10 +30,13 @@ There is 3 layers of control inside of the ModuleSettings.

 Allowing for greater control without having to edit hundreds of lines of code.   
 On top of that:   
-Any Setting that isn't "Present" is counted as "Enabled".    
+Any Setting that isn't "Present" can be defined as "Enabled" or "Disabled" using the "Default" argument.     
+If "Default" is missing, then it will just default to "Enabled".    
 So if you want to disable just 1 thing you can keep that 1 thing and delete the rest of the Setting.    
 It will still work as the same.    
 The default settings just come with everything so you can see what is controllable.   
+Note: If a global Module setting is disabled but a dependency needs said Module, it will enable only the required classes.    
+If a Module type (Float-Collection as example) is specifically disabled, the Dependency Resolver will throw errors telling you whats wrong.    

 How to compile the Code with the ModuleSettings enabled:
 ```
@@ -1,4 +1,5 @@
 {
+	"Default": true,
 	"Async": true,
 	"Base": true,
 	"Collection": true,
@@ -1,11 +1,12 @@
 ![build](https://github.com/Speiger/Primitive-Collections/actions/workflows/build_action.yml/badge.svg)
 [![Latest Release](https://jitpack.io/v/Speiger/Primitive-Collections.svg)](https://jitpack.io/#Speiger/Primitive-Collections)
+![Maven Central Version](https://img.shields.io/maven-central/v/io.github.speiger/Primitive-Collections)
 [![License](https://img.shields.io/badge/License-Apache_2.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
-![GitHub commit activity](https://img.shields.io/github/commit-activity/m/Speiger/Primitive-Collections)      
+![GitHub commit activity](https://img.shields.io/github/commit-activity/y/Speiger/Primitive-Collections)      
 ![Unit Tests](https://github.com/Speiger/Primitive-Collections/actions/workflows/build_tests_action.yml/badge.svg)
-![Coverage](https://gist.githubusercontent.com/Speiger/280257cd19cbe1dda3789bebd4ff65cf/raw/405abd1d2f6c19ac70f20b8b1772176f42d5c5d3/jacoco.svg)
+![Coverage](https://gist.githubusercontent.com/Speiger/280257cd19cbe1dda3789bebd4ff65cf/raw/jacoco.svg)
 [![codecov](https://codecov.io/gh/Speiger/Primitive-Collections/branch/debug/graph/badge.svg?token=WSTSNJM0EN)](https://codecov.io/gh/Speiger/Primitive-Collections)
-![Tests Done](https://gist.githubusercontent.com/Speiger/280257cd19cbe1dda3789bebd4ff65cf/raw/405abd1d2f6c19ac70f20b8b1772176f42d5c5d3/tests.svg)
+![Tests Done](https://gist.githubusercontent.com/Speiger/280257cd19cbe1dda3789bebd4ff65cf/raw/tests.svg)
 # Primitive-Collections
 This is a Simple Primitive Collections Library aimed to outperform Java's Collection Library and FastUtil.  
 Both in Performance and Quality of Life Features.  
@@ -43,7 +44,7 @@ To ensure that problems can be dealt with even if it is breaking the current API

 # How to install
 Using Jitpack Gradle
-```gradle
+```groovy
 repositories {
    maven {
        url = "https://jitpack.io"
@@ -54,6 +55,13 @@ dependencies {
 }
 ```

+Using Maven Central
+```groovy
+dependencies {
+	implementation 'io.github.speiger:Primitive-Collections:0.9.0'
+}
+```
+
 # SourceCode
 The generated Sourcecode can be automatically build,    
 but if you want to just browse around in it.    
@@ -0,0 +1,15 @@
+# Security Policy
+
+## Supported Versions
+
+Due to how the releases work, only the latest versions will be supported.
+
+## Reporting a Vulnerability
+
+If you have discovered a security vulnerability in this project, please report it privately.     
+**Please refrain from posting in public issues.**     
+This gives me time to process issues that are being found, and reduces the possiblity of abuse while patches are being created.   
+Please disclose it [here](https://github.com/Speiger/Primitive-Collections/security/advisories/new).
+
+Please consider that this project is developed by a single person.    
+So please provide a reasonable timeframe when reporting.    
@@ -10,6 +10,7 @@ tasks.withType(JavaCompile) {
 apply plugin: 'java'
 apply plugin: 'eclipse'
 apply plugin: 'maven-publish'
+apply plugin: 'signing'

 repositories {
    mavenCentral()
@@ -19,16 +20,22 @@ repositories {
 }

 archivesBaseName = 'Primitive Collections'
-version = '0.9.0';
+version = RELEASE_VERSION;

 sourceCompatibility = targetCompatibility = compileJava.sourceCompatibility = compileJava.targetCompatibility = JavaVersion.current();

 System.out.println("Java Version: "+compileJava.sourceCompatibility)

+java {
+	withJavadocJar()
+    withSourcesJar()
+}
+
 javadoc {
    options.tags = [ "implSpec", "note" ] 
 }

+
 eclipse {
 	classpath {
 		downloadJavadoc = true
@@ -40,6 +47,7 @@ sourceSets {
    builder
 }

+
 configurations {
 	builderCompile.extendsFrom compile
 }
@@ -48,7 +56,7 @@ dependencies {
 	builderImplementation 'com.google.code.gson:gson:2.10'
 	builderImplementation 'de.speiger:Simple-Code-Generator:1.3.0'
    testImplementation 'junit:junit:4.12'
-    testImplementation 'com.google.guava:guava-testlib:31.0.1-jre'
+    testImplementation 'com.google.guava:guava-testlib:33.6.0-jre'
    
 }

@@ -99,26 +107,12 @@ task generateLimitSource(type: JavaExec) {
 	args = ['silent', 'load']
 }

-task javadocJar(type: Jar) {
-    from javadoc
-    archiveClassifier = 'javadoc'
-}
-
-task srcJar(type: Jar) {
-    from sourceSets.main.allSource
-    archiveClassifier = 'sources'
-}
-
 compileJava.dependsOn generateGithubSource

 javadoc.failOnError = false
 javadoc.options.memberLevel = JavadocMemberLevel.PUBLIC
 javadoc.options.quiet()

-artifacts {
-    archives javadocJar
-    archives srcJar
-}

 task testBooleans(type: Test) {
 	group 'tests'
@@ -268,13 +262,10 @@ jacocoTestReport {
    }
 }

+
 publishing {
-	Properties props = new Properties()
-	if(file("$buildDir/credentials.properties").exists()) {
-		props.load(new FileInputStream("$buildDir/credentials.properties"))
-	}
 	publications {
-		mavenJava(MavenPublication) {
+		personal(MavenPublication) {
 			pom {
 				name = 'Primitive Collections'
 				description = 'A Primitive Collection library that reduces memory usage and improves performance'
@@ -283,8 +274,6 @@ publishing {
 				artifactId = project.archivesBaseName.replace(" ", "-")
 				groupId = 'de.speiger'
 				from components.java
-				artifact tasks.srcJar
-				artifact tasks.javadocJar
 				licenses {
 					license {
 						name = 'The Apache License, Version 2.0'
@@ -309,11 +298,83 @@ publishing {
 	}
 	repositories {
 		maven {
+			name = "Speiger_Maven"
+			def auth = System.getenv("Speiger_Maven_Auth")?.split(';');
 			url version.endsWith('SNAPSHOT') ? "https://maven.speiger.com/repository/debug" : "https://maven.speiger.com/repository/main"
 			credentials(PasswordCredentials) {
-				username props.mavenUser
-				password props.mavenPassword
+				username auth?[0]
+				password auth?[1]
 			}
 		}
 	}
 }
+
+tasks.withType(PublishToMavenRepository) {
+    def predicate = provider {
+        (repository == publishing.repositories.mavenCentral && publication == publishing.publications.maven) ||
+        (repository != publishing.repositories.mavenCentral && publication != publishing.publications.maven)
+    }
+    onlyIf("publishing binary to the external repository, or binary and sources to the internal one") {
+        predicate.get()
+    }
+}
+
+tasks.withType(PublishToMavenLocal) {
+    def predicate = provider {
+        publication == publishing.publications.personal
+    }
+    onlyIf("publishing binary and sources") {
+        predicate.get()
+    }
+}
+
+//Maven central Start
+//Disabling due to java8 incompat, only needed to manually publishing anyways
+
+//signing.useGpgCmd()
+//
+//import com.vanniktech.maven.publish.SonatypeHost
+//import com.vanniktech.maven.publish.JavaLibrary
+//import com.vanniktech.maven.publish.JavadocJar
+//
+//mavenPublishing {
+//  configure(new JavaLibrary(new JavadocJar.None(), true))
+//}
+//
+//mavenPublishing {
+//    publishToMavenCentral(SonatypeHost.CENTRAL_PORTAL)
+//
+//    signAllPublications()
+//    pom {
+//		name = 'Primitive Collections'
+//		description = 'A Primitive Collection library that reduces memory usage and improves performance'
+//		url = 'https://github.com/Speiger/Primitive-Collections'
+//		version = project.version	
+//		group = 'io.github.speiger'
+//        licenses {
+//            license {
+//				name = 'The Apache License, Version 2.0'
+//				url = 'http://www.apache.org/licenses/LICENSE-2.0.txt'
+//            }
+//        }
+//
+//        developers {
+//			developer {
+//				id = 'speiger'
+//				name = 'Speiger'
+//			}
+//        }
+//
+//        scm {
+//            connection = 'scm:git:git://github.com/Speiger/Primitive-Collections.git'
+//            developerConnection = 'scm:git:ssh://github.com:Speiger/Primitive-Collections.git'
+//            url = 'https://github.com/Speiger/Primitive-Collections'
+//        }
+//                
+//        issueManagement {
+//			system = 'github'
+//			url = 'https://github.com/Speiger/Primitive-Collections/issues'
+//		}
+//    }
+//}
+//
@@ -1,4 +1,6 @@
 org.gradle.jvmargs=-Xmx3G

-maxMemory = 1024m
-testThreads = 2
+maxMemory = 2048m
+testThreads = 4
+
+RELEASE_VERSION = 0.9.0
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.10-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
@@ -128,6 +128,7 @@ public class PrimitiveCollectionsBuilder extends TemplateProcessor
 		for(int i = 0,m=modules.size();i<m;i++) {
 			modules.get(i).setManager(manager);
 		}
+		manager.resolve();
 		for(int i = 0,m=modules.size();i<m;i++) {
 			biPackages.forEach(modules.get(i)::init);
 		}
@@ -1,54 +1,100 @@
 package speiger.src.builder;

 import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
 import java.nio.file.Files;
 import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
 import java.util.Set;
+import java.util.TreeMap;
 import java.util.TreeSet;

+import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
 import com.google.gson.internal.Streams;
 import com.google.gson.stream.JsonWriter;

+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.IDependency.LoadingState;
 import speiger.src.builder.modules.BaseModule;

@SuppressWarnings("javadoc")
 public class SettingsManager
 {
 	boolean loaded;
+	Map<String, LoadingState> parsedData = new TreeMap<>();
 	JsonObject data = new JsonObject();
 	Set<String> moduleNames = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
+	Set<IDependency> allDependencies = new LinkedHashSet<>();
 	
-	public boolean isModuleEnabled(BaseModule base, ClassType keyType, ClassType valueType) {
-		if(!loaded) return true;
-		if(!isEnabled(data, base.getModuleName())) return false;
-		JsonObject result = getObject(data, keyType.getClassPath(), false);
-		if(!isEnabled(result, "Enabled")) return false;
-		if(base.isBiModule()) {
-			result = getObject(result, valueType.getClassPath(), false);
-			if(!isEnabled(result, "Enabled")) return false;
+	public void resolve() {
+		if(!loaded) return;
+		Set<IDependency> roots = new LinkedHashSet<>();
+		Set<IDependency> leafs = new LinkedHashSet<>();
+		for(IDependency entry : allDependencies) {
+			if(entry.isRoot()) {
+				roots.add(entry);
+			}
+			if(entry.isLeaf()) {
+				leafs.add(entry);
+			}
+		}
+		/**
+		 * This has to be 2 iteration passes.
+		 * Due to Key Value Pairs, first pass does all initials keys, and the second pass processes the values.
+		 * May require more passes but extremely unlikely
+		 */
+		for(int i = 0;i<2;i++) {
+			for(ClassType keyType : ModulePackage.TYPE) {
+				for(ClassType valueType : ModulePackage.TYPE) {
+					for(IDependency entry : roots) {
+						entry.resolveRequirements(keyType, valueType);
+					}
+				}
+			}
 		}
-		result = getObject(result, base.getModuleName(), false);
-		return (result.size() <= 0 || isEnabled(result, "Enabled")) && base.areDependenciesLoaded();		
-	}
 		
-	public boolean isModuleEnabled(BaseModule base, ClassType keyType, ClassType valueType, String entry)
-	{
-		if(!loaded) return true;
-		if(!isEnabled(data, base.getModuleName())) return false;
-		JsonObject result = getObject(data, keyType.getClassPath(), false);
-		if(!isEnabled(result, "Enabled")) return false;
-		if(base.isBiModule()) {
-			result = getObject(result, valueType.getClassPath(), false);
-			if(!isEnabled(result, "Enabled")) return false;
+		List<String> errors = new ArrayList<>();
+		for(ClassType keyType : ModulePackage.TYPE) {
+			for(ClassType valueType : ModulePackage.TYPE) {
+				for(IDependency entry : leafs) {
+					entry.validateDependency(errors::add, keyType, valueType);
+				}
+			}
+		}
+		if(errors.size() > 0) {
+			throw new IllegalStateException("Issues with dependencies found: "+String.join("\n", errors));
 		}
-		result = getObject(result, base.getModuleName(), false);
-		return (result.size() <= 0 || (isEnabled(result, "Enabled") && isEnabled(result, entry))) && base.areDependenciesLoaded();
 	}
 	
 	public void addModule(BaseModule module) {
-		if(loaded) return;
+		if(loaded) {
+			if(module.isBiModule()) {
+				for(ClassType keyType : ModulePackage.TYPE) {
+					for(ClassType valueType : ModulePackage.TYPE) {
+						if(!module.isModuleValid(keyType, valueType)) continue;
+						for(IDependency dependency : module.getDependencies(keyType, valueType)) {
+							dependency.set(parsedData);
+							allDependencies.add(dependency);
+						}
+					}
+				}
+				return;
+			}
+			for(ClassType keyType : ModulePackage.TYPE) {
+				if(!module.isModuleValid(keyType, keyType)) continue;
+				for(IDependency dependency : module.getDependencies(keyType, keyType)) {
+					dependency.set(parsedData);
+					allDependencies.add(dependency);
+				}
+			}
+			return;
+		}
 		String moduleName = module.getModuleName();
 		moduleNames.add(moduleName);
 		data.addProperty(moduleName, true);
@@ -57,9 +103,9 @@ public class SettingsManager
 				for(ClassType valueType : ModulePackage.TYPE) {
 					if(!module.isModuleValid(keyType, valueType)) continue;
 					JsonObject obj = new JsonObject();
-					obj.addProperty("Enabled", true);
-					for(String key : module.getModuleKeys(keyType, valueType)) {
-						obj.addProperty(key, true);
+					for(IDependency dependency : module.getDependencies(keyType, valueType)) {
+						String key = dependency.getName();
+						if(key != null) obj.addProperty(key, true);
 					}
 					addModule(keyType, valueType, true, moduleName, obj);
 				}
@@ -69,18 +115,61 @@ public class SettingsManager
 		for(ClassType keyType : ModulePackage.TYPE) {
 			if(!module.isModuleValid(keyType, keyType)) continue;
 			JsonObject obj = new JsonObject();
-			obj.addProperty("Enabled", true);
-			for(String key : module.getModuleKeys(keyType, keyType)) {
-				obj.addProperty(key, true);
+			for(IDependency dependency : module.getDependencies(keyType, keyType)) {
+				String key = dependency.getName();
+				if(key != null) obj.addProperty(key, true);
 			}
 			addModule(keyType, keyType, false, moduleName, obj);			
 		}
 	}
 	
+	public void printModuleSettings(List<BaseModule> modules) {
+		JsonObject data = new JsonObject();
+		for(BaseModule module : modules) {
+			String moduleName = module.getModuleName();
+			if(module.isBiModule()) {
+				for(ClassType keyType : ModulePackage.TYPE) {
+					for(ClassType valueType : ModulePackage.TYPE) {
+						if(!module.isModuleValid(keyType, valueType)) continue;
+						JsonObject obj = new JsonObject();
+						for(IDependency dependency : module.getDependencies(keyType, valueType)) {
+							String key = dependency.getName();
+							if(key != null) obj.addProperty(key, dependency.isLoaded(keyType, valueType).getJsonResult());
+						}
+						addModule(data, keyType, valueType, true, moduleName, obj);
+					}
+				}
+				continue;
+			}
+			for(ClassType keyType : ModulePackage.TYPE) {
+				if(!module.isModuleValid(keyType, keyType)) continue;
+				JsonObject obj = new JsonObject();
+				for(IDependency dependency : module.getDependencies(keyType, keyType)) {
+					String key = dependency.getName();
+					if(key != null) obj.addProperty(key, dependency.isLoaded(keyType, keyType).getJsonResult());
+				}
+				addModule(data, keyType, keyType, false, moduleName, obj);			
+			}
+		}
+		try {
+			System.out.println();
+			JsonWriter writer = new JsonWriter(new OutputStreamWriter(System.out));
+			writer.setIndent("\t");
+			Streams.write(data, writer);
+			writer.flush();
+			System.out.println();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+	
 	public void load() {
 		try(BufferedReader reader = Files.newBufferedReader(Paths.get("ModulSettings.json"))) {
 			data = JsonParser.parseReader(reader).getAsJsonObject();
 			loaded = true;
+			IDependency.flatten("", false, data, parsedData);
+			JsonElement element = data.get("Default");
+			LoadingState.setOptionalResolver(LoadingState.of(element == null ? true : element.getAsBoolean()));
 		}
 		catch(Exception e) { e.printStackTrace(); }
 	}
@@ -100,6 +189,14 @@ public class SettingsManager
 		catch(Exception e) { e.printStackTrace(); }
 	}
 	
+	private void addModule(JsonObject data, ClassType keyType, ClassType valueType, boolean bi, String moduleName, JsonObject obj) {
+		JsonObject result = getObject(data, keyType.getClassPath(), true);
+		if(bi) {
+			result = getObject(result, valueType.getClassPath(), true);
+		}
+		result.add(moduleName, obj);
+	}
+	
 	private void addModule(ClassType keyType, ClassType valueType, boolean bi, String moduleName, JsonObject obj) {
 		JsonObject result = getObject(data, keyType.getClassPath(), true);
 		if(bi) {
@@ -117,9 +214,4 @@ public class SettingsManager
 		}
 		return obj;
 	}
-	
-	private boolean isEnabled(JsonObject obj, String key) {
-		if(obj.has(key)) return obj.getAsJsonPrimitive(key).getAsBoolean();
-		return true;
-	}
 }
@@ -0,0 +1,137 @@
+package speiger.src.builder.dependencies;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.StringJoiner;
+import java.util.TreeSet;
+import java.util.function.Consumer;
+
+import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.Requirements.Requirement;
+
+@SuppressWarnings("javadoc")
+public abstract class BaseDependency implements IDependency {
+	protected static boolean FETCH_FAILURES = false;
+	protected static Set<String> FAILURE_KEYS = new TreeSet<>();
+	
+	protected final String name;
+	protected final boolean biType;
+	protected Map<String, LoadingState> dependencies;
+	protected List<IDependency> children = new ArrayList<>();
+	protected List<Requirement> requirements = new ArrayList<>();
+	protected ClassType keyType;
+	protected ClassType valueType;
+	
+	public BaseDependency(String name, boolean biType) {
+		this.name = name;
+		this.biType = biType;
+	}
+	
+	@Override
+	public String toString() {
+		return name;
+	}
+	
+	@Override
+	public void set(Map<String, LoadingState> dependency) {
+		dependencies = dependency;
+	}
+	
+	@Override
+	public IDependency addDependency(Requirement require) {
+		requirements.add(require);
+		require.dependency.addChild(this);
+		return this;
+	}
+	
+	@Override
+	public void addChild(IDependency child) {
+		children.add(child);
+	}
+	
+	@Override
+	public boolean isLeaf() {
+		return children.isEmpty();
+	}
+	
+	@Override
+	public boolean isRoot() {
+		return requirements.isEmpty();
+	}
+	
+	protected LoadingState getGlobalState() {
+		return dependencies.getOrDefault(name, LoadingState.OPTIONAL);
+	}
+	
+	@Override
+	public String getLocalStateKey(ClassType keyType, ClassType valueType) {
+		return (biType ? keyType.getClassPath()+"-"+valueType.getClassPath() : keyType.getClassPath())+"-"+name;
+	}
+	
+	protected LoadingState getLocalState(ClassType keyType, ClassType valueType) {
+		return dependencies.getOrDefault(getLocalStateKey(keyType, valueType), LoadingState.OPTIONAL);
+	}
+		
+	protected LoadingState getReqirementState(ClassType keyType, ClassType valueType) {
+		LoadingState state = requirements.isEmpty() ? LoadingState.REQUIRED : LoadingState.OPTIONAL;
+		for(int i = 0,m=requirements.size();i<m;i++) {
+			state = state.merge(requirements.get(i).test(keyType, valueType));
+		}
+		return state.resolveIfUndefined();
+	}
+	
+	@Override
+	public void resolveRequirements(ClassType keyType, ClassType valueType) {
+		if(!children.isEmpty()) {
+			for(IDependency child : children) {
+				if(child == this) continue;
+				child.resolveRequirements(keyType, valueType);
+			}
+		}
+		if(getLocalState(keyType, valueType) == LoadingState.REQUIRED) {
+			for(Requirement req : requirements) {
+				dependencies.putIfAbsent(req.key(keyType, valueType), LoadingState.REQUIRED);
+			}
+		}
+	}
+	
+	@Override
+	public void validateDependency(Consumer<String> result, ClassType keyType, ClassType valueType) {
+		if(getLocalState(keyType, valueType) == LoadingState.REQUIRED) {
+			FETCH_FAILURES = true;
+			for(Requirement req : requirements) {
+				req.test(keyType, valueType);
+			}
+			FETCH_FAILURES = false;
+			if(FAILURE_KEYS.size() > 0) {
+				int size = FAILURE_KEYS.size();
+				StringJoiner joiner = new StringJoiner("], [", "[", "]");
+				FAILURE_KEYS.forEach(joiner::add);
+				FAILURE_KEYS.clear();
+				String joins = size > 1 ? "["+joiner.toString()+"]" : joiner.toString();
+				
+				result.accept("["+getLocalStateKey(keyType, valueType)+"] Requires "+joins+" but it specifically has been disabled!");
+			}
+			
+		}
+	}
+	
+	@Override
+	public void set(ClassType key, ClassType value) {
+		this.keyType = key;
+		this.valueType = value;
+	}
+	
+	@Override
+	public boolean isEnabled() {
+		if(keyType == null || keyType == null) return false;
+		return isLoaded(keyType, valueType).getJsonResult();
+	}
+	
+	@Override
+	public String getName() {
+		return name;
+	}
+}
@@ -0,0 +1,29 @@
+package speiger.src.builder.dependencies;
+
+import speiger.src.builder.ClassType;
+
+@SuppressWarnings("javadoc")
+public class FunctionDependency extends BaseDependency {
+	ModuleDependency owner;
+	
+	public FunctionDependency(ModuleDependency owner, String name) {
+		super(name, owner.biType);
+		this.owner = owner;
+	}
+	
+	@Override
+	public LoadingState isLoaded(ClassType key, ClassType value) {
+		if(dependencies == null) return LoadingState.REQUIRED;
+		LoadingState result = getLocalState(key, value);
+		if(FETCH_FAILURES && result == LoadingState.REJECTED) {
+			FAILURE_KEYS.add(getLocalStateKey(key, value));
+		}
+		return result.resolveIfUndefined().merge(getReqirementState(key, value));
+	}
+	
+	@Override
+	public String getLocalStateKey(ClassType keyType, ClassType valueType) {
+		return (biType ? keyType.getClassPath()+"-"+valueType.getClassPath() : keyType.getClassPath())+"-"+owner.getName()+"-"+name;
+	}
+
+}
@@ -0,0 +1,104 @@
+package speiger.src.builder.dependencies;
+
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.function.Consumer;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonPrimitive;
+
+import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.Requirements.Requirement;
+
+@SuppressWarnings("javadoc")
+public interface IDependency {
+	
+	
+	public void set(Map<String, LoadingState> dependency);
+	public void set(ClassType key, ClassType value);
+	public LoadingState isLoaded(ClassType key, ClassType value);
+	public String getLocalStateKey(ClassType keyType, ClassType valueType);
+	public boolean isEnabled();
+	public boolean isLeaf();
+	public boolean isRoot();
+	
+	public String getName();
+	public void validateDependency(Consumer<String> result, ClassType keyType, ClassType valueType);
+	public void resolveRequirements(ClassType keyType, ClassType valueType);
+	
+	public void addChild(IDependency child);
+	public <T extends IDependency> T addDependency(Requirement require);
+	public default <T extends IDependency> T addKeyDependency(IDependency dependency) { return addDependency(new Requirement(dependency, Requirements.KEY_TEST, Requirements.KEY_GETTER)); }
+	public default <T extends IDependency> T addValueDependency(IDependency dependency) { return addDependency(new Requirement(dependency, Requirements.VALUE_TEST, Requirements.VALUE_GETTER)); }
+	public default <T extends IDependency> T addEntryDependency(IDependency dependency) { return addDependency(new Requirement(dependency, Requirements.ENTRY_TEST, Requirements.ENTRY_GETTER)); }
+	public default <T extends IDependency> T addTypeDependency(IDependency dependency, ClassType type) { return addDependency(new Requirement(dependency, Requirements.typedTest(type), Requirements.typedKey(type))); }
+	public default <T extends IDependency> T addOptionalTypeDependency(IDependency dependency, ClassType type, boolean key) { return addDependency(new Requirement(dependency, Requirements.optionalTest(type, key), Requirements.optionalKey(type, key))); }
+	public default <T extends IDependency> T addOptionalTypeDependency(ClassType type, boolean key) { return addDependency(new Requirement(this, Requirements.optionalTest(type, key), Requirements.optionalKey(type, key))); }
+
+	
+	public static void flatten(String prefix, boolean applyMiddle, JsonObject object, Map<String, LoadingState> result) {
+		if(applyMiddle) prefix+="-";
+		for(Entry<String, JsonElement> entry : object.entrySet()) {
+			String key = entry.getKey();
+			JsonElement value = entry.getValue();
+			if(value instanceof JsonPrimitive) {
+				String entryKey = prefix+key;
+				if("Enabled".equalsIgnoreCase(key)) {
+					entryKey = prefix.substring(0, prefix.length()-1);
+				}
+				result.put(entryKey, LoadingState.of(((JsonPrimitive)value).getAsBoolean()));
+			}
+			if(value instanceof JsonObject) {
+				flatten(prefix+key, true, (JsonObject)value, result);
+			}
+		}
+	}
+	
+	public static enum LoadingState {
+		OPTIONAL,
+		REQUIRED,
+		REJECTED;
+		
+		private static LoadingState RESOLVED = LoadingState.REQUIRED;
+		
+		public static LoadingState of(boolean value) {
+			return value ? REQUIRED : REJECTED;
+		}
+		
+		public LoadingState merge(LoadingState merge) {
+			return ordinal() > merge.ordinal() ? this : merge;
+		}
+		
+		public LoadingState replaceIfUndefined(LoadingState state) {
+			return this == OPTIONAL ? state : this;
+		}
+		
+		public LoadingState resolveIfUndefined() {
+			return this == OPTIONAL ? RESOLVED : this;
+		}
+		
+		public LoadingState mergeDown(LoadingState merge) {
+			if(merge == REJECTED || ordinal() > merge.ordinal()) {
+				return this;
+			}
+			return merge;
+		}
+		
+		public LoadingState mergeUp(LoadingState merge) {
+			if(merge == REQUIRED || ordinal() > merge.ordinal()) {
+				return this;
+			}
+			return merge;
+		}
+		
+		public static void setOptionalResolver(LoadingState state) {
+			RESOLVED = state;
+		}
+		
+		public boolean getJsonResult() {
+			LoadingState state = this == OPTIONAL ? RESOLVED : this;
+			return state == REQUIRED;
+		}
+	}
+}
@@ -0,0 +1,31 @@
+package speiger.src.builder.dependencies;
+
+import speiger.src.builder.ClassType;
+import speiger.src.builder.modules.BaseModule;
+
+@SuppressWarnings("javadoc")
+public class ModuleDependency extends BaseDependency {
+	BaseModule owner;
+	
+	public ModuleDependency(BaseModule owner, boolean biType) {
+		super(owner.getModuleName(), biType);
+		this.owner = owner;
+	}
+	
+	public FunctionDependency createDependency(String name) {
+		FunctionDependency result = new FunctionDependency(this, name);
+		if(biType) result.addEntryDependency(this);
+		else result.addKeyDependency(this);
+		return result;
+	}
+	
+	@Override
+	public LoadingState isLoaded(ClassType key, ClassType value) {
+		if(dependencies == null) return LoadingState.REQUIRED;
+		LoadingState result = getLocalState(key, value);
+		if(FETCH_FAILURES && result == LoadingState.REJECTED) {
+			FAILURE_KEYS.add(getLocalStateKey(key, value));
+		}
+		return result.replaceIfUndefined(getGlobalState()).resolveIfUndefined().merge(getReqirementState(key, value));
+	}
+}
@@ -0,0 +1,68 @@
+package speiger.src.builder.dependencies;
+
+import java.util.function.Consumer;
+
+import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.IDependency.LoadingState;
+
+@SuppressWarnings("javadoc")
+public class Requirements {
+	public static final RequirementTest KEY_TEST = (T, K, V) -> T.isLoaded(K, K);
+	public static final RequirementTest VALUE_TEST = (T, K, V) -> T.isLoaded(V, V);
+	public static final RequirementTest ENTRY_TEST = (T, K, V) -> T.isLoaded(K, V);
+	
+	public static RequirementTest typedTest(ClassType type) {
+		return (T, K, V) -> T.isLoaded(type, type);
+	}
+	
+	public static RequirementTest optionalTest(ClassType type, boolean key) {
+		return (T, K, V) -> (key ? K : V) != type ? T.isLoaded(type, type) : LoadingState.REQUIRED;
+	}
+	
+	public static final RequirementKey KEY_GETTER = (T, K, V) -> T.getLocalStateKey(K, K);
+	public static final RequirementKey VALUE_GETTER = (T, K, V) -> T.getLocalStateKey(V, V);
+	public static final RequirementKey ENTRY_GETTER = (T, K, V) -> T.getLocalStateKey(K, V);
+	
+	public static RequirementKey typedKey(ClassType type) {
+		return (T, K, V) -> T.getLocalStateKey(type, type);
+	}
+	
+	public static RequirementKey optionalKey(ClassType type, boolean key) {
+		return (T, K, V) -> (key ? K : V) != type ? T.getLocalStateKey(type, type) : "";
+	}
+
+	
+	
+	public interface RequirementTest {
+		public LoadingState test(IDependency test, ClassType keyType, ClassType valueType);
+	}
+	
+	public static interface RequirementKey {
+		public String key(IDependency test, ClassType keyType, ClassType valueType);
+	}
+	
+	public static interface RequirementResolver {
+		public void resolve(IDependency test, Consumer<String> result, ClassType keyType, ClassType valueType);
+	}
+	
+	public static class Requirement {
+		IDependency dependency;
+		RequirementTest test;
+		RequirementKey key;
+		
+		public Requirement(IDependency dependency, RequirementTest test, RequirementKey key) {
+			this.dependency = dependency;
+			this.test = test;
+			this.key = key;
+		}
+		
+		public LoadingState test(ClassType keyType, ClassType valueType) {
+			return test.test(dependency, keyType, valueType);
+		}
+		
+		public String key(ClassType keyType, ClassType valueType) {
+			return key.key(dependency, keyType, valueType);
+		}
+		
+	}
+}
@@ -1,9 +1,17 @@
 package speiger.src.builder.modules;

+import java.util.Arrays;
+import java.util.List;
+
+import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;
+
@SuppressWarnings("javadoc")
 public class AsyncModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new AsyncModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false).addKeyDependency(JavaModule.MODULE);
 	
 	@Override
 	public String getModuleName() { return "Async"; }
@@ -16,16 +24,16 @@ public class AsyncModule extends BaseModule
 	@Override
 	protected void loadFunctions() {}
 	@Override
-	public boolean areDependenciesLoaded() { return isDependencyLoaded(CollectionModule.INSTANCE); }
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE); }
 	@Override
 	protected void loadBlockades() {
-		if(!isModuleEnabled()) {
+		if(!MODULE.isEnabled()) {
 			addBlockedFiles("AsyncBuilder", "Task");
 		}
 	}
 	@Override
 	protected void loadFlags() {
-		if(isModuleEnabled()) {
+		if(MODULE.isEnabled()) {
 			addKeyFlag("ASYNC_MODULE");
 		}
 	}
@@ -1,13 +1,15 @@
 package speiger.src.builder.modules;

 import java.util.Collections;
-import java.util.Set;
+import java.util.List;
+import java.util.function.Consumer;
 import java.util.function.Predicate;

 import speiger.src.builder.ClassType;
 import speiger.src.builder.ModulePackage;
 import speiger.src.builder.RequiredType;
 import speiger.src.builder.SettingsManager;
+import speiger.src.builder.dependencies.IDependency;
 import speiger.src.builder.mappers.ArgumentMapper;
 import speiger.src.builder.mappers.InjectMapper;
 import speiger.src.builder.mappers.LineMapper;
@@ -30,6 +32,9 @@ public abstract class BaseModule
 		this.entry = entry;
 		keyType = entry.getKeyType();
 		valueType = entry.getValueType();
+		for(IDependency dependency : getDependencies(keyType, valueType)) {
+			dependency.set(keyType, valueType);
+		}
 		loadVariables();
 		loadClasses();
 		loadTestClasses();
@@ -56,32 +61,12 @@ public abstract class BaseModule
 	
 	public abstract String getModuleName();
 	public boolean isBiModule() { return false; }
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) { return Collections.emptySet(); }
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Collections.emptyList(); }
 	public boolean isModuleValid(ClassType keyType, ClassType valueType) { return true; }
 	
 	public ClassType keyType() { return keyType; }
 	public ClassType valueType() { return valueType; }
 	
-	protected boolean isModuleEnabled() {
-		return manager == null || manager.isModuleEnabled(this, keyType, valueType);
-	}
-	
-	protected boolean isModuleEnabled(String name) {
-		return manager == null || manager.isModuleEnabled(this, keyType, valueType, name);
-	}
-	
-	protected boolean isDependencyLoaded(BaseModule module) {
-		return isDependencyLoaded(module, true);
-	}
-	
-	protected boolean isDependencyLoaded(BaseModule module, boolean key) {
-		return manager == null || (module.isBiModule() ? manager.isModuleEnabled(module, keyType, valueType) : (key ? manager.isModuleEnabled(module, keyType, keyType) : manager.isModuleEnabled(module, valueType, valueType))); 
-	}
-	
-	public boolean areDependenciesLoaded() {
-		return true;
-	}
-	
 	protected void addFlag(String name) {
 		entry.addFlag(name);
 	}
@@ -205,4 +190,9 @@ public abstract class BaseModule
 		entry.addMapper(mapper);
 		return mapper;
 	}
+	
+	public static <T> T make(T input, Consumer<T> processor) {
+		processor.accept(input);
+		return input;
+	}
 }
@@ -1,52 +1,59 @@
 package speiger.src.builder.modules;

 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;

 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;

@SuppressWarnings("javadoc")
 public class CollectionModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new CollectionModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false)
+			.addKeyDependency(FunctionModule.MODULE)
+			.addOptionalTypeDependency(FunctionModule.MODULE, ClassType.OBJECT, true)
+			.addOptionalTypeDependency(FunctionModule.MODULE, ClassType.INT, true)
+			.addOptionalTypeDependency(ClassType.OBJECT, true);
+	public static final FunctionDependency STREAMS = MODULE.createDependency("Streams");
+	public static final FunctionDependency SPLIT_ITERATORS = MODULE.createDependency("Splititerators").addKeyDependency(STREAMS);
+	public static final FunctionDependency IARRAY = MODULE.createDependency("IArray");
+	public static final FunctionDependency STRATEGY = MODULE.createDependency("Strategy");
 	
 	@Override
 	public String getModuleName() { return "Collection"; }
 	@Override
 	protected void loadVariables() {}
 	@Override
-	public boolean areDependenciesLoaded(){ return isDependencyLoaded(JavaModule.INSTANCE); }
-	
-	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType)
-	{
-		return new TreeSet<>(Arrays.asList("Streams", "Splititerators", "IArray", "Strategy"));
-	}
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE, STREAMS, SPLIT_ITERATORS, IARRAY, STRATEGY); }
 	
 	@Override
 	protected void loadFlags() {
-		if(isModuleEnabled()) addKeyFlag("COLLECTION_MODULE");
-		if(isModuleEnabled("Streams")) addKeyFlag("STREAM_FEATURE");
-		if(isModuleEnabled("Splititerators")) addKeyFlag("SPLIT_ITERATOR_FEATURE");
-		if(isModuleEnabled("IArray")) addKeyFlag("IARRAY_FEATURE");
+		if(MODULE.isEnabled()) addKeyFlag("COLLECTION_MODULE");
+		if(STREAMS.isEnabled()) addKeyFlag("STREAM_FEATURE");
+		if(SPLIT_ITERATORS.isEnabled()) addKeyFlag("SPLIT_ITERATOR_FEATURE");
+		if(IARRAY.isEnabled()) addKeyFlag("IARRAY_FEATURE");
 	}
 	
 	@Override
 	protected void loadBlockades() {
-		if(!isModuleEnabled()) {
+		if(!MODULE.isEnabled()) {
 			addBlockedFiles("Iterable", "Iterables", "Iterator", "Iterators", "BidirectionalIterator", "ListIterator");
-			addBlockedFiles("Arrays", "Collection", "AbstractCollection", "Collections", "Stack");
+			addBlockedFiles("Arrays", "Collection", "OrderedCollection", "AbstractCollection", "Collections", "Stack");
 		}
-		if(!isModuleEnabled("Splititerators")) addBlockedFiles("Splititerator", "Splititerators");
-		if(!isModuleEnabled("IArray")) addBlockedFiles("IArray");
-		if(!isModuleEnabled("Strategy")) addBlockedFiles("Strategy");
+		if(!SPLIT_ITERATORS.isEnabled()) addBlockedFiles("Splititerator", "Splititerators");
+		if(!IARRAY.isEnabled()) addBlockedFiles("IArray");
+		if(!STRATEGY.isEnabled()) addBlockedFiles("Strategy");
 		
-		if(keyType.isObject()) {
+		if(keyType.isObject())
+		{
 			addBlockedFiles("Stack");
 			addBlockedFiles("CollectionStreamTester");
 		}
-		if(keyType == ClassType.BOOLEAN) {
+		if(keyType == ClassType.BOOLEAN)
+		{
 			addBlockedFiles("CollectionRemoveIfTester", "CollectionStreamTester");
 			addBlockedFilter(T -> T.endsWith("Tester") && T.startsWith("Iterable"));
 		}
@@ -84,6 +91,7 @@ public class CollectionModule extends BaseModule
 	{
 		//Abstract Classes
 		addAbstractMapper("ABSTRACT_COLLECTION", "Abstract%sCollection");
+		addAbstractMapper("REVERSED_ORDERED_COLLECTION", "Reverse%sOrderedCollection");
 		
 		//Helper Classes
 		addClassMapper("ARRAYS", "Arrays");
@@ -94,6 +102,7 @@ public class CollectionModule extends BaseModule
 		
 		//Interfaces
 		addClassMapper("COLLECTION", "Collection");
+		addClassMapper("ORDERED_COLLECTION", "OrderedCollection");
 		addClassMapper("ITERABLE", "Iterable");
 		addClassMapper("SPLIT_ITERATOR", "Splititerator");
 		addClassMapper("LIST_ITERATOR", "ListIterator");
@@ -1,12 +1,18 @@
 package speiger.src.builder.modules;

+import java.util.Arrays;
+import java.util.List;
+
 import speiger.src.builder.ClassType;
 import speiger.src.builder.RequiredType;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;

@SuppressWarnings("javadoc")
 public class FunctionModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new FunctionModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false).addKeyDependency(JavaModule.MODULE);
 	
 	@Override
 	public String getModuleName() { return "Function"; }
@@ -19,10 +25,17 @@ public class FunctionModule extends BaseModule
 	@Override
 	protected void loadTestClasses() {}
 	
+	@Override
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) {
+		return Arrays.asList(MODULE);
+	}
+	
 	@Override
 	protected void loadBlockades()
 	{
 		if(keyType.isObject()) addBlockedFiles("Consumer", "Comparator");
+		if(!MODULE.isEnabled()) addBlockedFiles("Consumer", "BiConsumer", "Comparator", "Supplier", "Optional", "Function", "UnaryOperator");
+		if(!keyType.needsCustomJDKType()) addBlockedFiles("Optional");
 	}
 	
 	@Override
@@ -48,6 +61,7 @@ public class FunctionModule extends BaseModule
 		}
 		else addBiRequirement("Function");
 		addRemapper("BiConsumer", "%sConsumer");
+		addRemapper("Optional", "Optional%s");
 	}
 	
 	@Override
@@ -82,6 +96,8 @@ public class FunctionModule extends BaseModule
 		
 		addFunctionMappers("PREDICATE", "%sPredicate");
 		addClassMapper("SUPPLIER", "Supplier");
+		addSimpleMapper("OPTIONAL", keyType.isObject() ? "Optional" : String.format("Optional%s", keyType.getFileType()));
+		addSimpleMapper("VALUE_OPTIONAL", valueType.isObject() ? "Optional" : String.format("Optional%s", valueType.getFileType()));
 		addAbstractMapper("SINGLE_UNARY_OPERATOR", "%1$s%1$sUnaryOperator");
 		addBiClassMapper("UNARY_OPERATOR", "UnaryOperator", "");
 		if(keyType.isObject())
@@ -1,11 +1,17 @@
 package speiger.src.builder.modules;

+import java.util.Arrays;
+import java.util.List;
+
 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;

@SuppressWarnings("javadoc")
 public class JavaModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new JavaModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false);
 	
 	@Override
 	public String getModuleName() { return "Base"; }
@@ -17,6 +23,11 @@ public class JavaModule extends BaseModule
 		loadBaseVariables();
 	}
 	
+	@Override
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) {
+		return Arrays.asList(MODULE);
+	}
+	
 	@Override
 	protected void loadFlags()
 	{
@@ -49,6 +60,8 @@ public class JavaModule extends BaseModule
 		addSimpleMapper("APPLY_KEY_VALUE", keyType.isObject() ? "apply" : "applyAs"+keyType.getNonFileType());
 		addSimpleMapper("APPLY_VALUE", valueType.isObject() ? "apply" : "applyAs"+valueType.getNonFileType());
 		addSimpleMapper("APPLY_CAST", "applyAs"+keyType.getCustomJDKType().getNonFileType());
+		addSimpleMapper("GET_OPTIONAL", keyType.isObject() ? "ofNullable" : "of");
+		addSimpleMapper("GET_OPTIONAL_VALUE", valueType.isObject() ? "ofNullable" : "of");
 		
 		//Shared by Maps and Pairs so moved to java.
 		addFunctionMappers("ENTRY_KEY", "get%sKey");
@@ -185,6 +198,7 @@ public class JavaModule extends BaseModule
 		addComment("@Type", "@param <%s> the keyType of elements maintained by this Collection");
 		addValueComment("@ValueArrayType", "@param <%s> the keyType of array that the operation should be applied");
 		addValueComment("@ValueType", "@param <%s> the keyType of elements maintained by this Collection");
+		addSimpleMapper("@Java21", getVersion() >= 21 ? "@Override" : "");
 		addAnnontion("@PrimitiveOverride", "@Override");
 		addSimpleMapper("@PrimitiveDoc", "");
 		addAnnontion("@Primitive", "@Deprecated");
@@ -1,55 +1,57 @@
 package speiger.src.builder.modules;

 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;

 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;

@SuppressWarnings("javadoc")
 public class ListModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new ListModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false).addKeyDependency(CollectionModule.MODULE).addKeyDependency(CollectionModule.SPLIT_ITERATORS);
+	public static final FunctionDependency IMPLEMENTATION = MODULE.createDependency("Implementations");
+	public static final FunctionDependency WRAPPERS = MODULE.createDependency("Wrappers");
+	public static final FunctionDependency ARRAY_LIST = MODULE.createDependency("ArrayList").addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency LINKED_LIST = MODULE.createDependency("LinkedList").addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency IMMUTABLE_LIST = MODULE.createDependency("ImmutableList").addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency COPY_ON_WRITE_LIST = MODULE.createDependency("CopyOnWriteList").addKeyDependency(IMPLEMENTATION);
 	
 	@Override
 	public String getModuleName() { return "List"; }
 	@Override
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE, IMPLEMENTATION, WRAPPERS, ARRAY_LIST, LINKED_LIST, IMMUTABLE_LIST, COPY_ON_WRITE_LIST); }
+	@Override
 	protected void loadVariables() {}
 	@Override
 	protected void loadFlags() {
-		if(isModuleEnabled()) addKeyFlag("LIST_MODULE");
-		if(isModuleEnabled("Wrappers")) addKeyFlag("LISTS_FEATURE");
-		boolean implementations = isModuleEnabled("Implementations");
-		if(implementations && isModuleEnabled("ArrayList")) addKeyFlag("ARRAY_LIST_FEATURE");
-		if(implementations && isModuleEnabled("LinkedList")) addKeyFlag("LINKED_LIST_FEATURE");
-		if(implementations && isModuleEnabled("ImmutableList")) addKeyFlag("IMMUTABLE_LIST_FEATURE");
-		if(implementations && isModuleEnabled("CopyOnWriteList")) addKeyFlag("COPY_ON_WRITE_LIST_FEATURE");
+		if(MODULE.isEnabled()) addKeyFlag("LIST_MODULE");
+		if(WRAPPERS.isEnabled()) addKeyFlag("LISTS_FEATURE");
+		if(ARRAY_LIST.isEnabled()) addKeyFlag("ARRAY_LIST_FEATURE");
+		if(LINKED_LIST.isEnabled()) addKeyFlag("LINKED_LIST_FEATURE");
+		if(IMMUTABLE_LIST.isEnabled()) addKeyFlag("IMMUTABLE_LIST_FEATURE");
+		if(COPY_ON_WRITE_LIST.isEnabled()) addKeyFlag("COPY_ON_WRITE_LIST_FEATURE");
 	}
 	
 	@Override
 	protected void loadBlockades()
 	{
-		if(!isModuleEnabled("Wrappers")) addBlockedFiles("Lists");
-		boolean implementations = !isModuleEnabled("Implementations");
-		if(implementations || !isModuleEnabled("ArrayList")) addBlockedFiles("ArrayList");
-		if(implementations || !isModuleEnabled("LinkedList")) addBlockedFiles("LinkedList");
-		if(implementations || !isModuleEnabled("ImmutableList")) addBlockedFiles("ImmutableList");
-		if(implementations || !isModuleEnabled("CopyOnWriteList")) addBlockedFiles("CopyOnWriteList");
-		if(!isModuleEnabled()) addBlockedFiles("List", "AbstractList");
+		if(!WRAPPERS.isEnabled()) addBlockedFiles("Lists");
+		if(!ARRAY_LIST.isEnabled()) addBlockedFiles("ArrayList");
+		if(!LINKED_LIST.isEnabled()) addBlockedFiles("LinkedList");
+		if(!IMMUTABLE_LIST.isEnabled()) addBlockedFiles("ImmutableList");
+		if(!COPY_ON_WRITE_LIST.isEnabled()) addBlockedFiles("CopyOnWriteList");
+		if(!MODULE.isEnabled()) addBlockedFiles("List", "AbstractList");
+		
 		
 		if(keyType.isObject()) addBlockedFiles("ListFillBufferTester");
 		if(keyType == ClassType.BOOLEAN) addBlockedFiles("ListFillBufferTester", "ListReplaceAllTester");
 	}
 	
-	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) {
-		return new TreeSet<>(Arrays.asList("Implementations", "Wrappers", "ArrayList", "LinkedList", "ImmutableList", "CopyOnWriteList"));
-	}

-	@Override
-	public boolean areDependenciesLoaded() {
-		return isDependencyLoaded(CollectionModule.INSTANCE);
-	}
 	
 	@Override
 	protected void loadRemappers()
@@ -1,15 +1,48 @@
 package speiger.src.builder.modules;

+import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;

 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;

@SuppressWarnings("javadoc")
 public class MapModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new MapModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, true)
+			.addKeyDependency(SetModule.MODULE)
+			.addValueDependency(CollectionModule.MODULE)
+			.addEntryDependency(SetModule.MODULE)
+			.addTypeDependency(SetModule.MODULE, ClassType.OBJECT);
+	public static final FunctionDependency IMPLEMENTATION = MODULE.createDependency("Implementations");
+	public static final FunctionDependency WRAPPERS = MODULE.createDependency("Wrappers").addKeyDependency(SetModule.WRAPPERS).addOptionalTypeDependency(SetModule.WRAPPERS, ClassType.OBJECT, true);
+
+	public static final FunctionDependency ORDERED_MAP = MODULE.createDependency("OrderedMap").addKeyDependency(SetModule.ORDERED_SET).addOptionalTypeDependency(SetModule.ORDERED_SET, ClassType.OBJECT, true);
+	public static final FunctionDependency SORTED_MAP = MODULE.createDependency("SortedMap").addKeyDependency(SetModule.SORTED_SET).addOptionalTypeDependency(SetModule.SORTED_SET, ClassType.OBJECT, true);
+
+	public static final FunctionDependency ARRAY_MAP = MODULE.createDependency("ArrayMap").addEntryDependency(ORDERED_MAP).addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency IMMUTABLE_MAP = MODULE.createDependency("ImmutableMap").addEntryDependency(IMPLEMENTATION);
+
+	public static final FunctionDependency HASH_MAP = MODULE.createDependency("HashMap").addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency LINKED_MAP = MODULE.createDependency("LinkedHashMap").addEntryDependency(HASH_MAP).addEntryDependency(ORDERED_MAP);
+	
+	public static final FunctionDependency CUSTOM_MAP = MODULE.createDependency("CustomHashMap").addEntryDependency(IMPLEMENTATION).addKeyDependency(CollectionModule.STRATEGY);
+	public static final FunctionDependency LINKED_CUSTOM_MAP = MODULE.createDependency("LinkedCustomHashMap").addEntryDependency(CUSTOM_MAP).addEntryDependency(ORDERED_MAP);
+
+	public static final FunctionDependency ENUM_MAP = MODULE.createDependency("EnumMap").addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency LINKED_ENUM_MAP = MODULE.createDependency("LinkedEnumMap").addEntryDependency(ENUM_MAP).addEntryDependency(ORDERED_MAP);
+	
+	public static final FunctionDependency REF_MAP = MODULE.createDependency("ReferenceHashMap").addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency LINKED_REF_MAP = MODULE.createDependency("LinkedReferenceMap").addEntryDependency(REF_MAP).addEntryDependency(ORDERED_MAP);
+
+	
+	public static final FunctionDependency CONCURRENT_MAP = MODULE.createDependency("ConcurrentMap").addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency AVL_TREE_MAP = MODULE.createDependency("AVLTreeMap").addEntryDependency(SORTED_MAP).addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency RB_TREE_MAP = MODULE.createDependency("RBTreeMap").addEntryDependency(SORTED_MAP).addEntryDependency(IMPLEMENTATION);
 	
 	@Override
 	public String getModuleName() { return "Map"; }
@@ -20,79 +53,58 @@ public class MapModule extends BaseModule
 	@Override
 	public boolean isModuleValid(ClassType keyType, ClassType valueType) { return keyType != ClassType.BOOLEAN; }
 	@Override
-	public boolean areDependenciesLoaded() { return isDependencyLoaded(SetModule.INSTANCE) && isDependencyLoaded(CollectionModule.INSTANCE, false); }
-	
-	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) {
-		Set<String> sets = new TreeSet<>();
-		sets.addAll(Arrays.asList("Wrappers", "Implementations"));
-		sets.addAll(Arrays.asList("OrderedMap", "SortedMap"));
-		sets.addAll(Arrays.asList("ArrayMap", "ConcurrentMap", "ImmutableMap"));
-		sets.addAll(Arrays.asList("HashMap", "LinkedHashMap"));
-		sets.addAll(Arrays.asList("CustomHashMap", "LinkedCustomHashMap"));
-		sets.addAll(Arrays.asList("EnumMap", "LinkedEnumMap"));
-		sets.addAll(Arrays.asList("AVLTreeMap", "RBTreeMap"));
-		return sets;
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) {
+		List<IDependency> dependencies = new ArrayList<>(Arrays.asList(MODULE, ORDERED_MAP, SORTED_MAP, IMPLEMENTATION, WRAPPERS, ARRAY_MAP, IMMUTABLE_MAP, HASH_MAP, LINKED_MAP, CUSTOM_MAP, LINKED_CUSTOM_MAP, CONCURRENT_MAP, AVL_TREE_MAP, RB_TREE_MAP));
+		if(keyType == ClassType.OBJECT) dependencies.addAll(Arrays.asList(ENUM_MAP, LINKED_ENUM_MAP, REF_MAP, LINKED_REF_MAP));
+		return dependencies;
 	}
 	
 	@Override
 	protected void loadFlags()
 	{
-		if(isModuleEnabled()) addFlag("MAP_MODULE");
-		if(isModuleEnabled("Wrappers")) addFlag("MAPS_FEATURE");
-		boolean implementations = isModuleEnabled("Implementations");
-		boolean hashMap = implementations && isModuleEnabled("HashMap");
-		boolean customHashMap = implementations && isModuleEnabled("CustomHashMap");
-		boolean enumMap = implementations && isModuleEnabled("EnumMap");
+		if(MODULE.isEnabled()) addFlag("MAP_MODULE");
+		if(WRAPPERS.isEnabled()) addFlag("MAPS_FEATURE");
+		if(ORDERED_MAP.isEnabled()) addFlag("ORDERED_MAP_FEATURE");
+		if(ARRAY_MAP.isEnabled()) addFlag("ARRAY_MAP_FEATURE");
+		if(LINKED_MAP.isEnabled()) addFlag("LINKED_MAP_FEATURE");
+		if(LINKED_CUSTOM_MAP.isEnabled()) addFlag("LINKED_CUSTOM_MAP_FEATURE");
+		if(LINKED_ENUM_MAP.isEnabled()) addFlag("LINKED_ENUM_MAP_FEATURE");
 		
-		if(isModuleEnabled("OrderedMap")) {
-			addFlag("ORDERED_MAP_FEATURE");
-			if(isModuleEnabled("ArrayMap")) addFlag("ARRAY_MAP_FEATURE");
-			if(hashMap && isModuleEnabled("LinkedHashMap")) addFlag("LINKED_MAP_FEATURE");
-			if(customHashMap && isModuleEnabled("LinkedCustomHashMap")) addFlag("LINKED_CUSTOM_MAP_FEATURE");
-			if(enumMap && isModuleEnabled("LinkedEnumMap")) addFlag("LINKED_ENUM_MAP_FEATURE");
-		}
-		if(isModuleEnabled("SortedMap")) {
-			addFlag("SORTED_MAP_FEATURE");
-			if(implementations && isModuleEnabled("AVLTreeMap")) addFlag("AVL_TREE_MAP_FEATURE");
-			if(implementations && isModuleEnabled("RBTreeMap")) addFlag("RB_TREE_MAP_FEATURE");
-		}
-		if(implementations && isModuleEnabled("ConcurrentMap")) addFlag("CONCURRENT_MAP_FEATURE");
-		if(implementations && isModuleEnabled("ImmutableMap")) addFlag("IMMUTABLE_MAP_FEATURE");
-		if(hashMap) addFlag("MAP_FEATURE");
-		if(customHashMap) addFlag("CUSTOM_MAP_FEATURE");
-		if(enumMap) addFlag("ENUM_MAP_FEATURE");
+		if(SORTED_MAP.isEnabled()) addFlag("SORTED_MAP_FEATURE");
+		if(AVL_TREE_MAP.isEnabled()) addFlag("AVL_TREE_MAP_FEATURE");
+		if(RB_TREE_MAP.isEnabled()) addFlag("RB_TREE_MAP_FEATURE");
+		
+		if(REF_MAP.isEnabled()) addFlag("REF_MAP_FEATURE");
+		if(LINKED_REF_MAP.isEnabled()) addFlag("LINKED_REF_MAP_FEATURE");
+		
+		
+		if(CONCURRENT_MAP.isEnabled()) addFlag("CONCURRENT_MAP_FEATURE");
+		if(IMMUTABLE_MAP.isEnabled()) addFlag("IMMUTABLE_MAP_FEATURE");
+		if(HASH_MAP.isEnabled()) addFlag("MAP_FEATURE");
+		if(CUSTOM_MAP.isEnabled()) addFlag("CUSTOM_MAP_FEATURE");
+		if(ENUM_MAP.isEnabled()) addFlag("ENUM_MAP_FEATURE");
 	}
 	
 	@Override
 	protected void loadBlockades()
 	{
-		if(!isModuleEnabled()) addBlockedFiles("Map", "AbstractMap");
-		if(!isModuleEnabled("Wrappers")) addBlockedFiles("Maps");
-		boolean implementations = !isModuleEnabled("Implementations");
-		if(implementations || !isModuleEnabled("ImmutableMap")) addBlockedFiles("ImmutableOpenHashMap");
-		if(implementations || !isModuleEnabled("ConcurrentMap")) addBlockedFiles("ConcurrentMap", "ConcurrentOpenHashMap");
-		
-		boolean ordered = !isModuleEnabled("OrderedMap");
-		if(ordered) addBlockedFiles("OrderedMap");
-		boolean hashMap = implementations || !isModuleEnabled("HashMap");
-		if(hashMap) addBlockedFiles("OpenHashMap");
-		if(hashMap || ordered || !isModuleEnabled("LinkedHashMap")) addBlockedFiles("LinkedOpenHashMap");
-		
-		boolean customHashMap = implementations || !isModuleEnabled("CustomHashMap");
-		if(customHashMap) addBlockedFiles("OpenCustomHashMap");
-		if(customHashMap || ordered || !isModuleEnabled("LinkedCustomHashMap")) addBlockedFiles("LinkedOpenCustomHashMap");
-		
-		boolean enumMap = implementations || !isModuleEnabled("EnumMap");
-		if(enumMap) addBlockedFiles("EnumMap");
-		if(enumMap || ordered || !isModuleEnabled("LinkedEnumMap")) addBlockedFiles("LinkedEnumMap");
-		
-		if(ordered || !isModuleEnabled("ArrayMap")) addBlockedFiles("ArrayMap");
-		
-		boolean sorted = !isModuleEnabled("SortedMap");
-		if(sorted) addBlockedFiles("SortedMap", "NavigableMap");
-		if(implementations || sorted || !isModuleEnabled("AVLTreeMap")) addBlockedFiles("AVLTreeMap");
-		if(implementations || sorted || !isModuleEnabled("RBTreeMap")) addBlockedFiles("RBTreeMap");
+		if(!MODULE.isEnabled()) addBlockedFiles("Map", "AbstractMap");
+		if(!WRAPPERS.isEnabled()) addBlockedFiles("Maps");
+		if(!IMMUTABLE_MAP.isEnabled()) addBlockedFiles("ImmutableOpenHashMap");
+		if(!CONCURRENT_MAP.isEnabled()) addBlockedFiles("ConcurrentMap", "ConcurrentOpenHashMap");
+		if(!ORDERED_MAP.isEnabled()) addBlockedFiles("OrderedMap");
+		if(!REF_MAP.isEnabled()) addBlockedFiles("ReferenceHashMap");
+		if(!LINKED_REF_MAP.isEnabled()) addBlockedFiles("LinkedReferenceHashMap");
+		if(!HASH_MAP.isEnabled()) addBlockedFiles("OpenHashMap");
+		if(!LINKED_MAP.isEnabled()) addBlockedFiles("LinkedOpenHashMap");
+		if(!CUSTOM_MAP.isEnabled()) addBlockedFiles("OpenCustomHashMap");
+		if(!LINKED_CUSTOM_MAP.isEnabled()) addBlockedFiles("LinkedOpenCustomHashMap");
+		if(!ENUM_MAP.isEnabled()) addBlockedFiles("EnumMap");
+		if(!LINKED_ENUM_MAP.isEnabled()) addBlockedFiles("LinkedEnumMap");
+		if(!ARRAY_MAP.isEnabled()) addBlockedFiles("ArrayMap");
+		if(!SORTED_MAP.isEnabled()) addBlockedFiles("SortedMap", "NavigableMap");
+		if(!AVL_TREE_MAP.isEnabled()) addBlockedFiles("AVLTreeMap");
+		if(!RB_TREE_MAP.isEnabled()) addBlockedFiles("RBTreeMap");
 		
 		if(keyType == ClassType.BOOLEAN)
 		{
@@ -125,6 +137,8 @@ public class MapModule extends BaseModule
 		addBiRequirement("AbstractMap");
 		addEnumRequirement("EnumMap");
 		addEnumRequirement("LinkedEnumMap");
+		addEnumRequirement("ReferenceHashMap");
+		addEnumRequirement("LinkedReferenceHashMap");
 		addBiRequirement("ConcurrentOpenHashMap");
 		addBiRequirement("ImmutableOpenHashMap");
 		addBiRequirement("OpenHashMap");
@@ -139,6 +153,8 @@ public class MapModule extends BaseModule
 		addRemapper("AbstractMap", "Abstract%sMap");
 		addRemapper("EnumMap", "Enum2%sMap");
 		addRemapper("LinkedEnumMap", "LinkedEnum2%sMap");
+		addRemapper("ReferenceHashMap", "Reference2%sHashMap");
+		addRemapper("LinkedReferenceHashMap", "Reference2%sLinkedHashMap");
 		addRemapper("ImmutableOpenHashMap", "Immutable%sOpenHashMap");
 		
 		//Test Classes
@@ -196,6 +212,7 @@ public class MapModule extends BaseModule
 		addBiRequirement("SortedMapNavigationTester");
 		addBiRequirement("OrderedMapNavigationTester");
 		addBiRequirement("OrderedMapMoveTester");
+		addBiRequirement("OrderedMapPutTester");
 		addBiRequirement("MapConstructorTester");
 		
 		addRemapper("TestMapGenerator", "Test%sMapGenerator");
@@ -246,11 +263,14 @@ public class MapModule extends BaseModule
 		addBiClassMapper("RB_TREE_MAP", "RBTreeMap", "2");
 		addFunctionValueMappers("LINKED_ENUM_MAP", valueType.isObject() ? "LinkedEnum2ObjectMap" : "LinkedEnum2%sMap");
 		addFunctionValueMappers("ENUM_MAP", valueType.isObject() ? "Enum2ObjectMap" : "Enum2%sMap");
+		addFunctionValueMappers("REF_MAP", valueType.isObject() ? "Reference2ObjectHashMap" : "Reference2%sHashMap");
+		addFunctionValueMappers("LINKED_REF_MAP", valueType.isObject() ? "Reference2ObjectLinkedHashMap" : "Reference2%sLinkedHashMap");
 		addBiClassMapper("HASH_MAP", "OpenHashMap", "2");
 		addBiClassMapper("ARRAY_MAP", "ArrayMap", "2");
 		
 		//Abstract Classes
 		addAbstractBiMapper("ABSTRACT_MAP", "Abstract%sMap", "2");
+		addAbstractBiMapper("REVERSED_ORDERED_MAP", "Reversed%sOrderedMap", "2");
 		
 		//Helper Classes
 		addBiClassMapper("MAPS", "Maps", "2");
@@ -1,15 +1,26 @@
 package speiger.src.builder.modules;

 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;

 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;

@SuppressWarnings("javadoc")
 public class PairModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new PairModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, true).addKeyDependency(JavaModule.MODULE);
+	public static final FunctionDependency IMMUTABLE = MODULE.createDependency("Immutable");
+	public static final FunctionDependency MUTABLE = MODULE.createDependency("Mutable");
+
+	
+//	public static final DependencyModule MODULE = new BiTypeModule(INSTANCE);
+//	public static final DependencyFunction IMMUTABLE = MODULE.createFunction("Immutable");
+//	public static final DependencyFunction MUTABLE = MODULE.createFunction("Mutable");
+	
 	@Override
 	public String getModuleName() { return "Pair"; }
 	@Override
@@ -21,20 +32,20 @@ public class PairModule extends BaseModule
 	@Override
 	protected void loadTestClasses() {}
 	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) { return new TreeSet<>(Arrays.asList("Mutable", "Immutable")); }
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE, IMMUTABLE, MUTABLE); }
 	
 	@Override
 	protected void loadFlags() {
-		if(isModuleEnabled()) addFlag("PAIR_MODULE");
-		if(isModuleEnabled("Mutable")) addFlag("MUTABLE_PAIR");
-		if(isModuleEnabled("Immutable")) addFlag("IMMUTABLE_PAIR");
+		if(MODULE.isEnabled()) addFlag("PAIR_MODULE");
+		if(MUTABLE.isEnabled()) addFlag("MUTABLE_PAIR");
+		if(IMMUTABLE.isEnabled()) addFlag("IMMUTABLE_PAIR");
 	}
 	
 	@Override
 	protected void loadBlockades() {
-		if(!isModuleEnabled()) addBlockedFiles("Pair");
-		if(!isModuleEnabled("Mutable")) addBlockedFiles("MutablePair");
-		if(!isModuleEnabled("Immutable")) addBlockedFiles("ImmutablePair");
+		if(!MODULE.isEnabled()) addBlockedFiles("Pair");
+		if(!MUTABLE.isEnabled()) addBlockedFiles("MutablePair");
+		if(!IMMUTABLE.isEnabled()) addBlockedFiles("ImmutablePair");
 	}
 	
 	@Override
@@ -1,15 +1,26 @@
 package speiger.src.builder.modules;

 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;

 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;

@SuppressWarnings("javadoc")
 public class PrioQueueModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new PrioQueueModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false).addKeyDependency(CollectionModule.MODULE);
+	public static final FunctionDependency IMPLEMENTATION = MODULE.createDependency("Implementations");
+	public static final FunctionDependency WRAPPERS = MODULE.createDependency("Wrappers");
+	public static final FunctionDependency DEQUEUE = MODULE.createDependency("Dequeue");
+	
+	public static final FunctionDependency FIFO_QUEUE = MODULE.createDependency("FiFoQueue").addKeyDependency(DEQUEUE).addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency HEAP_QUEUE = MODULE.createDependency("HeapQueue").addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency ARRAY_PRIO_QUEUE = MODULE.createDependency("ArrayPrioQueue").addKeyDependency(IMPLEMENTATION);
+	
 	
 	@Override
 	public String getModuleName() { return "PriorityQueue"; }
@@ -18,36 +29,26 @@ public class PrioQueueModule extends BaseModule
 	@Override
 	protected void loadFunctions() {}
 	@Override
-	public boolean areDependenciesLoaded() { return isDependencyLoaded(CollectionModule.INSTANCE); }
-	
-	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) {
-		return new TreeSet<>(Arrays.asList("Wrappers", "Implementations", "Dequeue", "FiFoQueue", "HeapQueue", "ArrayPrioQueue"));
-	}
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE, WRAPPERS, IMPLEMENTATION, DEQUEUE, FIFO_QUEUE, HEAP_QUEUE, ARRAY_PRIO_QUEUE); }
 	
 	@Override
 	protected void loadFlags() {
-		if(isModuleEnabled()) addFlag("QUEUE_MODULE");
-		if(isModuleEnabled("Wrappers")) addKeyFlag("QUEUES_FEATURE");
-		boolean implementations = isModuleEnabled("Implementations");
-		if(isModuleEnabled("Dequeue")) {
-			addKeyFlag("DEQUEUE_FEATURE");
-			if(implementations && isModuleEnabled("FiFoQueue")) addKeyFlag("FIFO_QUEUE_FEATURE");
-		}
-		if(implementations && isModuleEnabled("HeapQueue")) addKeyFlag("HEAP_QUEUE_FEATURE");
-		if(implementations && isModuleEnabled("ArrayPrioQueue")) addKeyFlag("ARRAY_QUEUE_FEATURE");
+		if(MODULE.isEnabled()) addFlag("QUEUE_MODULE");
+		if(WRAPPERS.isEnabled()) addKeyFlag("QUEUES_FEATURE");
+		if(DEQUEUE.isEnabled()) addKeyFlag("DEQUEUE_FEATURE");
+		if(FIFO_QUEUE.isEnabled()) addKeyFlag("FIFO_QUEUE_FEATURE");
+		if(HEAP_QUEUE.isEnabled()) addKeyFlag("HEAP_QUEUE_FEATURE");
+		if(ARRAY_PRIO_QUEUE.isEnabled()) addKeyFlag("ARRAY_QUEUE_FEATURE");
 	}
 	
 	@Override
 	protected void loadBlockades() {
-		if(!isModuleEnabled()) addBlockedFiles("PriorityQueue", "AbstractPriorityQueue");
-		if(!isModuleEnabled("Wrappers")) addBlockedFiles("PriorityQueues");
-		boolean implementations = !isModuleEnabled("Implementations");
-		boolean dequeue = !isModuleEnabled("Dequeue");
-		if(dequeue) addBlockedFiles("PriorityDequeue"); 
-		if(dequeue || implementations || !isModuleEnabled("FiFoQueue")) addBlockedFiles("ArrayFIFOQueue");
-		if(implementations || !isModuleEnabled("HeapQueue")) addBlockedFiles("HeapPriorityQueue");
-		if(implementations || !isModuleEnabled("ArrayPrioQueue")) addBlockedFiles("ArrayPriorityQueue");
+		if(!MODULE.isEnabled()) addBlockedFiles("PriorityQueue", "AbstractPriorityQueue");
+		if(!WRAPPERS.isEnabled()) addBlockedFiles("PriorityQueues");
+		if(!DEQUEUE.isEnabled()) addBlockedFiles("PriorityDequeue");
+		if(!FIFO_QUEUE.isEnabled()) addBlockedFiles("ArrayFIFOQueue");
+		if(!HEAP_QUEUE.isEnabled()) addBlockedFiles("HeapPriorityQueue");
+		if(!ARRAY_PRIO_QUEUE.isEnabled()) addBlockedFiles("ArrayPriorityQueue");
 		
 		if(keyType == ClassType.BOOLEAN) {
 			addBlockedFiles("QueueTests");
@@ -1,15 +1,30 @@
 package speiger.src.builder.modules;

 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;

 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;

@SuppressWarnings("javadoc")
 public class SetModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new SetModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false).addKeyDependency(CollectionModule.MODULE).addKeyDependency(CollectionModule.SPLIT_ITERATORS);
+	public static final FunctionDependency IMPLEMENTATION = MODULE.createDependency("Implementations");
+	public static final FunctionDependency WRAPPERS = MODULE.createDependency("Wrappers");
+	public static final FunctionDependency ORDERED_SET = MODULE.createDependency("OrderedSet");
+	public static final FunctionDependency SORTED_SET = MODULE.createDependency("SortedSet");
+	public static final FunctionDependency ARRAY_SET = MODULE.createDependency("ArraySet").addKeyDependency(ORDERED_SET).addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency IMMUTABLE_SET = MODULE.createDependency("ImmutableSet").addKeyDependency(ORDERED_SET).addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency HASH_SET = MODULE.createDependency("HashSet").addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency LINKED_SET = MODULE.createDependency("LinkedHashSet").addKeyDependency(ORDERED_SET).addKeyDependency(HASH_SET);
+	public static final FunctionDependency CUSTOM_SET = MODULE.createDependency("CustomHashSet").addKeyDependency(IMPLEMENTATION).addKeyDependency(CollectionModule.STRATEGY);
+	public static final FunctionDependency LINKED_CUSTOM_SET = MODULE.createDependency("LinkedCustomHashSet").addKeyDependency(ORDERED_SET).addKeyDependency(CUSTOM_SET);
+	public static final FunctionDependency AVL_TREE_SET = MODULE.createDependency("AVLTreeSet").addKeyDependency(SORTED_SET).addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency RB_TREE_SET = MODULE.createDependency("RBTreeSet").addKeyDependency(SORTED_SET).addKeyDependency(IMPLEMENTATION);
 	
 	@Override
 	public String getModuleName() { return "Set"; }
@@ -19,68 +34,40 @@ public class SetModule extends BaseModule
 	@Override
 	public boolean isModuleValid(ClassType keyType, ClassType valueType) { return keyType != ClassType.BOOLEAN; }
 	@Override
-	public boolean areDependenciesLoaded() { return isDependencyLoaded(CollectionModule.INSTANCE); }
-	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) {
-		Set<String> sets = new TreeSet<>();
-		sets.addAll(Arrays.asList("Wrappers", "Implementations"));
-		sets.addAll(Arrays.asList("OrderedSet", "SortedSet"));
-		sets.addAll(Arrays.asList("ArraySet", "ImmutableSet"));
-		sets.addAll(Arrays.asList("HashSet", "LinkedHashSet"));
-		sets.addAll(Arrays.asList("CustomHashSet", "LinkedCustomHashSet"));
-		sets.addAll(Arrays.asList("AVLTreeSet", "RBTreeSet"));
-		return sets;
-	}
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE, WRAPPERS, ORDERED_SET, SORTED_SET, IMPLEMENTATION, ARRAY_SET, IMMUTABLE_SET, HASH_SET, LINKED_SET, CUSTOM_SET, LINKED_CUSTOM_SET, AVL_TREE_SET, RB_TREE_SET); }
 	
 	@Override
 	protected void loadFlags()
 	{
-		if(isModuleEnabled()) addFlag("SET_MODULE");
-		if(isModuleEnabled("Wrappers")) addFlag("SETS_FEATURE");
-		boolean implementations = isModuleEnabled("Implementations");
-		boolean hashSet = implementations && isModuleEnabled("HashSet");
-		boolean customHashSet = implementations && isModuleEnabled("CustomHashSet");
-		
-		if(isModuleEnabled("OrderedSet")) {
-			addFlag("ORDERED_SET_FEATURE");
-			if(implementations && isModuleEnabled("ArraySet")) addFlag("ARRAY_SET_FEATURE");
-			if(hashSet && isModuleEnabled("LinkedHashSet")) addFlag("LINKED_SET_FEATURE");
-			if(customHashSet && isModuleEnabled("LinkedCustomHashSet")) addFlag("LINKED_CUSTOM_SET_FEATURE");
-		}
-		if(isModuleEnabled("SortedSet")) {
-			addFlag("SORTED_SET_FEATURE");
-			if(implementations && isModuleEnabled("AVLTreeSet")) addFlag("AVL_TREE_SET_FEATURE");
-			if(implementations && isModuleEnabled("RBTreeSet")) addFlag("RB_TREE_SET_FEATURE");
-		}
-		if(implementations && isModuleEnabled("ImmutableSet")) addFlag("IMMUTABLE_SET_FEATURE");
-		if(hashSet) addFlag("HASH_SET_FEATURE");
-		if(customHashSet) addFlag("CUSTOM_HASH_SET_FEATURE");
+		if(MODULE.isEnabled()) addFlag("SET_MODULE");
+		if(WRAPPERS.isEnabled()) addFlag("SETS_FEATURE");
+		if(ORDERED_SET.isEnabled()) addFlag("ORDERED_SET_FEATURE");
+		if(SORTED_SET.isEnabled()) addFlag("SORTED_SET_FEATURE");
+		if(IMMUTABLE_SET.isEnabled()) addFlag("IMMUTABLE_SET_FEATURE");
+		if(ARRAY_SET.isEnabled()) addFlag("ARRAY_SET_FEATURE");
+		if(HASH_SET.isEnabled()) addFlag("HASH_SET_FEATURE");
+		if(LINKED_SET.isEnabled()) addFlag("LINKED_SET_FEATURE");
+		if(CUSTOM_SET.isEnabled()) addFlag("CUSTOM_HASH_SET_FEATURE");
+		if(LINKED_CUSTOM_SET.isEnabled()) addFlag("LINKED_CUSTOM_SET_FEATURE");
+		if(AVL_TREE_SET.isEnabled()) addFlag("AVL_TREE_SET_FEATURE");
+		if(RB_TREE_SET.isEnabled()) addFlag("RB_TREE_SET_FEATURE");
 	}
 	
 	@Override
 	protected void loadBlockades()
 	{
-		if(!isModuleEnabled()) addBlockedFiles("Set", "AbstractSet");
-		if(!isModuleEnabled("Wrappers")) addBlockedFiles("Sets");
-		boolean implementations = !isModuleEnabled("Implementations");
-		if(implementations || !isModuleEnabled("ImmutableSet")) addBlockedFiles("ImmutableOpenHashSet");
-		
-		boolean ordered = !isModuleEnabled("OrderedSet");
-		if(ordered) addBlockedFiles("OrderedSet");
-		boolean hashSet = implementations || !isModuleEnabled("HashSet");
-		if(hashSet) addBlockedFiles("OpenHashSet");
-		if(hashSet || ordered || !isModuleEnabled("LinkedHashSet")) addBlockedFiles("LinkedOpenHashSet");
-		
-		boolean customHashSet = implementations || !isModuleEnabled("CustomHashSet");
-		if(customHashSet) addBlockedFiles("OpenCustomHashSet");
-		if(customHashSet || ordered || !isModuleEnabled("LinkedCustomHashSet")) addBlockedFiles("LinkedOpenCustomHashSet");
-		
-		if(implementations || ordered || !isModuleEnabled("ArraySet")) addBlockedFiles("ArraySet");
-		
-		boolean sorted = !isModuleEnabled("SortedSet");
-		if(sorted) addBlockedFiles("SortedSet", "NavigableSet");
-		if(implementations || sorted || !isModuleEnabled("AVLTreeSet")) addBlockedFiles("AVLTreeSet");
-		if(implementations || sorted || !isModuleEnabled("RBTreeSet")) addBlockedFiles("RBTreeSet");
+		if(!MODULE.isEnabled()) addBlockedFiles("Set", "AbstractSet");
+		if(!WRAPPERS.isEnabled()) addBlockedFiles("Sets");
+		if(!IMMUTABLE_SET.isEnabled()) addBlockedFiles("ImmutableOpenHashSet");
+		if(!ORDERED_SET.isEnabled()) addBlockedFiles("OrderedSet");
+		if(!HASH_SET.isEnabled()) addBlockedFiles("OpenHashSet");
+		if(!LINKED_SET.isEnabled()) addBlockedFiles("LinkedOpenHashSet");
+		if(!CUSTOM_SET.isEnabled()) addBlockedFiles("OpenCustomHashSet");
+		if(!LINKED_CUSTOM_SET.isEnabled()) addBlockedFiles("LinkedOpenCustomHashSet");
+		if(!ARRAY_SET.isEnabled()) addBlockedFiles("ArraySet");
+		if(!SORTED_SET.isEnabled()) addBlockedFiles("SortedSet", "NavigableSet");
+		if(!AVL_TREE_SET.isEnabled()) addBlockedFiles("AVLTreeSet");
+		if(!RB_TREE_SET.isEnabled()) addBlockedFiles("RBTreeSet");
 		
 		if(keyType == ClassType.BOOLEAN)
 		{
@@ -161,6 +148,7 @@ public class SetModule extends BaseModule
 		
 		//Abstract Classes
 		addAbstractMapper("ABSTRACT_SET", "Abstract%sSet");
+		addAbstractMapper("REVERSED_ORDERED_SET", "Reversed%sOrderedSet");
 		
 		//Helper Classes
 		addClassMapper("SETS", "Sets");
@@ -1,12 +1,18 @@
 package speiger.src.collections.PACKAGE.collections;

 import java.util.Collection;
+#if ORDERED_MAP_FEATURE
+import java.util.function.Supplier;
+#endif
 import java.util.Objects;
 import java.util.AbstractCollection;
 #if TYPE_OBJECT
 import java.util.function.Consumer;
 #endif

+#if ORDERED_MAP_FEATURE
+import speiger.src.collections.PACKAGE.lists.LIST_ITERATOR;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 import speiger.src.collections.PACKAGE.utils.ITERATORS;
@@ -262,5 +268,79 @@ public abstract class ABSTRACT_COLLECTION KEY_GENERIC_TYPE extends AbstractColle
 		if (a.length > size()) a[size()] = EMPTY_KEY_VALUE;
 		return a;
 	}
+
+#endif
+#if ORDERED_MAP_FEATURE
+	public static class REVERSED_ORDERED_COLLECTION KEY_GENERIC_TYPE extends ABSTRACT_COLLECTION KEY_GENERIC_TYPE implements ORDERED_COLLECTION KEY_GENERIC_TYPE {
+		ORDERED_COLLECTION KEY_GENERIC_TYPE collection;
+		Supplier<ITERATOR KEY_GENERIC_TYPE> reverseIterator;
+		
+		public REVERSED_ORDERED_COLLECTION(ORDERED_COLLECTION KEY_GENERIC_TYPE collection, Supplier<ITERATOR KEY_GENERIC_TYPE> reverseIterator) {
+			this.collection = collection;
+			this.reverseIterator = reverseIterator;
+		}
+		
+		@Override
+		public boolean add(KEY_TYPE o) { return collection.add(o); }
+		@Override
+		public ORDERED_COLLECTION KEY_GENERIC_TYPE reversed() { return collection; }
+		@Override
+		public void addFirst(KEY_TYPE e) { collection.addLast(e); }
+		@Override
+		public void addLast(KEY_TYPE e) { collection.addFirst(e); }
+		@Override
+#if !TYPE_OBJECT
+		public boolean contains(KEY_TYPE e) { return collection.contains(e); }
+#else
+		public boolean contains(Object e) { return collection.contains(e); }
+#endif
+		@Override
+#if !TYPE_OBJECT
+		public boolean REMOVE_KEY(KEY_TYPE e) { return collection.REMOVE_KEY(e); }
+#else
+		public boolean remove(Object e) { return collection.remove(e); }
+#endif
+		@Override
+		public void clear() { collection.clear(); }
+		@Override
+		public KEY_TYPE GET_FIRST_KEY() { return collection.GET_LAST_KEY(); }
+		@Override
+		public KEY_TYPE REMOVE_FIRST_KEY() { return collection.REMOVE_LAST_KEY(); }
+		@Override
+		public KEY_TYPE GET_LAST_KEY() { return collection.GET_FIRST_KEY(); }
+		@Override
+		public KEY_TYPE REMOVE_LAST_KEY() { return collection.REMOVE_FIRST_KEY(); }
+		@Override
+		public ITERATOR KEY_GENERIC_TYPE iterator() { return reverseIterator.get(); }
+		@Override
+		public int size() { return collection.size(); }
+	}
+	
+	public static class ReverseBiIterator KEY_GENERIC_TYPE implements LIST_ITERATOR KEY_GENERIC_TYPE {
+		LIST_ITERATOR KEY_GENERIC_TYPE it;
+		
+		public ReverseBiIterator(LIST_ITERATOR KEY_GENERIC_TYPE it) {
+			this.it = it;
+		}
+		
+		@Override
+		public KEY_TYPE NEXT() { return it.PREVIOUS(); }
+		@Override
+		public boolean hasNext() { return it.hasPrevious(); }
+		@Override
+		public boolean hasPrevious() { return it.hasNext(); }
+		@Override
+		public KEY_TYPE PREVIOUS() { return it.NEXT(); }
+		@Override
+		public void remove() { it.remove(); }
+		@Override
+		public int nextIndex() { return it.previousIndex(); }
+		@Override
+		public int previousIndex() { return it.nextIndex(); }
+		@Override
+		public void set(KEY_TYPE e) { it.set(e); }
+		@Override
+		public void add(KEY_TYPE e) { it.add(e); }
+	}
 #endif
 }
@@ -1,19 +1,11 @@
 package speiger.src.collections.PACKAGE.collections;

-#if !TYPE_OBJECT
-import speiger.src.collections.objects.collections.ObjectBidirectionalIterator;
-/**
- * A Type-Specific {@link ObjectBidirectionalIterator} to reduce (un)boxing
- */
-public interface BI_ITERATOR KEY_GENERIC_TYPE extends ITERATOR KEY_GENERIC_TYPE, ObjectBidirectionalIterator<CLASS_TYPE>
-#else
 /**
 * This is a basically a {@link java.util.ListIterator} without the index functions.
 * Allowing to have a simple Bidirectional Iterator without having to keep track of the Iteration index.
 * @Type(T)
 */
 public interface BI_ITERATOR KEY_GENERIC_TYPE extends ITERATOR KEY_GENERIC_TYPE
-#endif
 {
 	/**
 	 * Returns true if the Iterator has a Previous element
@@ -29,11 +21,11 @@ public interface BI_ITERATOR KEY_GENERIC_TYPE extends ITERATOR KEY_GENERIC_TYPE
 	public KEY_TYPE PREVIOUS();
 	
 #if !TYPE_OBJECT
-	/** {@inheritDoc}
+	/**
 	 * <p>This default implementation delegates to the corresponding type-specific function.
 	 * @deprecated Please use the corresponding type-specific function instead. 
+	 * @return the Previous element of the iterator.+
 	 */
-	@Override
 	@Deprecated
 	public default CLASS_TYPE previous() {
 		return KEY_TO_OBJ(PREVIOUS());
@@ -5,6 +5,9 @@ import java.util.function.Consumer;
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
+#if JDK_TYPE 
+import java.util.OPTIONAL;
+#endif

 #if !TYPE_OBJECT

@@ -30,6 +33,9 @@ import speiger.src.collections.PACKAGE.collections.OUTPUT_ITERABLE;
 #endif
 #enditerate
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.PACKAGE.functions.function.TO_OBJECT_FUNCTION;
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
@@ -408,13 +414,13 @@ public interface ITERABLE KEY_GENERIC_TYPE extends Iterable<CLASS_TYPE>
 	 * @param filter that should be applied
 	 * @return the found value or the null equivalent variant.
 	 */
-	default KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	default OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(ITERATOR KEY_GENERIC_TYPE iter = iterator();iter.hasNext();) {
 			KEY_TYPE entry = iter.NEXT();
-			if(filter.test(entry)) return entry;
+			if(filter.test(entry)) return OPTIONAL.GET_OPTIONAL(entry);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -459,7 +465,7 @@ public interface ITERABLE KEY_GENERIC_TYPE extends Iterable<CLASS_TYPE>
 	 * @param operator the operation that should be applied
 	 * @return the reduction result, returns null value if nothing was found
 	 */
-	default KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	default OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -471,7 +477,7 @@ public interface ITERABLE KEY_GENERIC_TYPE extends Iterable<CLASS_TYPE>
 			}
 			state = operator.APPLY_VALUE(state, iter.NEXT());
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}	
 	
 	/**
@@ -0,0 +1,83 @@
+package speiger.src.collections.PACKAGE.collections;
+
+#if JAVA_VERSION>=21
+import java.util.SequencedCollection;
+
+public interface ORDERED_COLLECTION KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, SequencedCollection<CLASS_TYPE> {
+#else
+public interface ORDERED_COLLECTION KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE {
+#endif
+	@Java21
+	ORDERED_COLLECTION KEY_GENERIC_TYPE reversed();
+	
+	/**
+	 * A method to add an element to the start of a collection
+	 * @param e that should be added at the start.
+	 */
+	public void addFirst(KEY_TYPE e);
+	
+	/**
+	 * A method to add an element to the end of a collection
+	 * @param e that should be added at the end.
+	 */
+	public void addLast(KEY_TYPE e);
+	
+	/**
+	 * A method to get the first element in the collection
+	 * @return first element in the collection
+	 */
+	public KEY_TYPE GET_FIRST_KEY();
+	/**
+	 * A method to get and remove the first element in the collection
+	 * @return first element in the collection
+	 */
+	public KEY_TYPE REMOVE_FIRST_KEY();
+	/**
+	 * A method to get the last element in the collection
+	 * @return last element in the collection
+	 */
+	public KEY_TYPE GET_LAST_KEY();
+	/**
+	 * A method to get and remove the last element in the collection
+	 * @return last element in the collection
+	 */
+	public KEY_TYPE REMOVE_LAST_KEY();
+	
+#if JAVA_VERSION>=21 && !TYPE_OBJECT
+	@Override
+	@Deprecated
+	default void addFirst(CLASS_TYPE e) {
+		addFirst(OBJ_TO_KEY(e));
+	}
+	
+	@Override
+	@Deprecated
+	default void addLast(CLASS_TYPE e) {
+		addLast(OBJ_TO_KEY(e));
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE getFirst() {
+		return KEY_TO_OBJ(GET_FIRST_KEY());
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE getLast() {
+		return KEY_TO_OBJ(GET_LAST_KEY());
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeFirst() {
+		return KEY_TO_OBJ(REMOVE_FIRST_KEY());
+	}
+
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeLast() {
+		return KEY_TO_OBJ(REMOVE_LAST_KEY());
+	}
+#endif
+}
@@ -0,0 +1,89 @@
+package speiger.src.collections.PACKAGE.functions;
+
+import java.util.NoSuchElementException;
+import java.util.function.Supplier;
+
+public final class OPTIONAL KEY_GENERIC_TYPE {
+	private static final OPTIONAL NO_GENERIC_TYPE EMPTY = new OPTIONALBRACES();
+	
+	private final boolean isPresent;
+	private final KEY_TYPE value;
+	
+	private OPTIONAL() {
+		this.isPresent = false;
+		this.value = EMPTY_VALUE;
+	}
+	
+	private OPTIONAL(KEY_TYPE value) {
+		this.isPresent = true;
+		this.value = value;
+	}
+	
+	public static OPTIONAL KEY_GENERIC_TYPE empty() {
+		return EMPTY;
+	}
+	
+	public static OPTIONAL KEY_GENERIC_TYPE of(KEY_TYPE value) {
+		return new OPTIONALBRACES(value);
+	}
+	
+	public KEY_TYPE SUPPLY_GET() {
+		if(!isPresent) throw new NoSuchElementException("No value present");
+		return value;
+	}
+	
+	public boolean isPresent() {
+		return isPresent;
+	}
+	
+	public boolean isEmpty() {
+		return !isPresent;
+	}
+	
+	public void ifPresent(CONSUMER KEY_GENERIC_TYPE consumer) {
+		if(isPresent) consumer.accept(value);
+	}
+	
+    public void ifPresentOrElse(CONSUMER KEY_GENERIC_TYPE action, Runnable emptyAction) {
+        if (isPresent) action.accept(value);
+        else emptyAction.run();
+    }
+	
+	public KEY_TYPE orElse(KEY_TYPE other) {
+		return isPresent ? value : other;
+	}
+	
+	public KEY_TYPE orElseGet(SUPPLIER KEY_GENERIC_TYPE other) {
+		return isPresent ? value : other.SUPPLY_GET();
+	}
+	
+	public KEY_TYPE orElseThrow() {
+        if (!isPresent) throw new NoSuchElementException("No value present");
+		return value;
+	}
+	
+    public <X extends Throwable> KEY_TYPE orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
+    	if(isPresent) return value;
+    	else throw exceptionSupplier.get();
+    }
+    
+    @Override
+    public boolean equals(Object obj) {
+    	if(obj == this) return true;
+    	if(obj instanceof OPTIONAL) {
+    		OPTIONAL KEY_GENERIC_TYPE other = (OPTIONAL KEY_GENERIC_TYPE)obj;
+    		return (isPresent && other.isPresent ? KEY_EQUALS(value, other.value) : isPresent == other.isPresent);
+    	}
+    	return false;
+    }
+    
+    @Override
+    public int hashCode() {
+    	return isPresent ? KEY_TO_HASH(value) : 0;
+    }
+    
+    @Override
+    public String toString() {
+    	return isPresent ? "OPTIONAL["+value+"]" : "OPTIONAL.empty";
+    }
+}
@@ -11,11 +11,15 @@ import java.util.RandomAccess;
 import speiger.src.collections.PACKAGE.collections.ABSTRACT_COLLECTION;
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+#endif
 #if INT_LIST_MODULE && !TYPE_INT
 import speiger.src.collections.ints.lists.IntList;
 #endif
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 import speiger.src.collections.utils.SanityChecks;

 /**
@@ -532,9 +536,10 @@ public abstract class ABSTRACT_LIST KEY_GENERIC_TYPE extends ABSTRACT_COLLECTION
 		public int size() {
 			return size;
 		}
-		
+#if SPLIT_ITERATOR_FEATURE
 		@Override
 		public SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 16464); }
+#endif
 		
 		@Override
 		public LIST_ITERATOR KEY_GENERIC_TYPE listIterator(int index) {
@@ -7,6 +7,16 @@ import java.util.Comparator;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
+
+#endif
 #if TYPE_OBJECT
 #if IARRAY_FEATURE || TYPE_OBJECT
 import java.util.function.Consumer;
@@ -33,6 +43,9 @@ import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.STACK;
 #endif
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -219,6 +232,42 @@ public class ARRAY_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 		return list;
 	}
 	
+#endif
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a ArrayList
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, ObjectArrayList<T>, ObjectArrayList<T>> toList() {
+		return Collector.of(ObjectArrayList::new, ObjectArrayList::add, ObjectArrayList::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a ArrayList
+	 * @Type(T)
+	 * @return a list with the contents of the Stream
+	 */
+	public static <T> ARRAY_LIST KEY_GENERIC_TYPE toList(Stream<T> stream) {
+		return stream.collect(ObjectArrayList::new, ObjectArrayList::add, ObjectArrayList::merge);
+	}
+	
+	private ObjectArrayList<T> merge(ObjectArrayList<T> a) {
+		addAll(a);
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a ArrayList
+	 * @return a list with the contents of the Stream
+	 */
+	public static ARRAY_LIST toList(JAVA_STREAM stream) {
+		return stream.collect(ARRAY_LIST::new, ARRAY_LIST::add, ARRAY_LIST::addAll);
+	}
+	
+#endif
 #endif
 	/**
 	 * Appends the specified element to the end of this list.
@@ -682,12 +731,12 @@ public class ARRAY_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0;i<size;i++) {
-			if(filter.test(data[i])) return data[i];
+			if(filter.test(data[i])) return OPTIONAL.GET_OPTIONAL(data[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -714,7 +763,7 @@ public class ARRAY_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -726,7 +775,7 @@ public class ARRAY_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 			}
 			state = operator.APPLY_VALUE(state, data[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
@@ -8,6 +8,15 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
+#endif
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
@@ -33,6 +42,9 @@ import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.STACK;
 #endif
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -166,7 +178,42 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	}
 	
 #endif
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a CopyOnWriteArrayList
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, CopyOnWriteObjectArrayList<T>, CopyOnWriteObjectArrayList<T>> toList() {
+		return Collector.of(CopyOnWriteObjectArrayList::new, CopyOnWriteObjectArrayList::add, CopyOnWriteObjectArrayList::merge);
+	}
 	
+	/**
+	 * Collects a Stream to a CopyOnWriteArrayList
+	 * @Type(T)
+	 * @return a list with the contents of the Stream
+	 */
+	public static <T> CopyOnWriteObjectArrayList KEY_GENERIC_TYPE toList(Stream<T> stream) {
+		return stream.collect(CopyOnWriteObjectArrayList::new, CopyOnWriteObjectArrayList::add, CopyOnWriteObjectArrayList::merge);
+	}
+	
+	private CopyOnWriteObjectArrayList<T> merge(CopyOnWriteObjectArrayList<T> a) {
+		addAll(a);
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a CopyOnWriteArrayList
+	 * @return a list with the contents of the Stream
+	 */
+	public static COPY_ON_WRITE_LIST toList(JAVA_STREAM stream) {
+		return stream.collect(COPY_ON_WRITE_LIST::new, COPY_ON_WRITE_LIST::add, COPY_ON_WRITE_LIST::addAll);
+	}
+	
+#endif
+#endif
 	private void setArray(KEY_TYPE[] data) {
 		this.data = data;
 	}
@@ -535,7 +582,7 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	 * @return if the element was found.
 	 */
 	@Override
-	@Deprecated
+	@Primitive
 	public boolean contains(Object o) {
 		return indexOf(o) != -1;
 	}
@@ -546,7 +593,7 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	 * @return the index of the element if found. (if not found then -1)
 	 */
 	@Override
-	@Deprecated
+	@Primitive
 	public int indexOf(Object o) {
 		KEY_TYPE[] data = this.data;
 #if TYPE_OBJECT
@@ -570,7 +617,7 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	 * @return the last index of the element if found. (if not found then -1)
 	 */
 	@Override
-	@Deprecated
+	@Primitive
 	public int lastIndexOf(Object o) {
 		KEY_TYPE[] data = this.data;
 #if TYPE_OBJECT
@@ -810,13 +857,13 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		KEY_TYPE[] data = this.data;
 		for(int i = 0,m=data.length;i<m;i++) {
-			if(filter.test(data[i])) return data[i];
+			if(filter.test(data[i])) return OPTIONAL.GET_OPTIONAL(data[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -845,7 +892,7 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE[] data = this.data;
 		KEY_TYPE state = EMPTY_VALUE;
@@ -858,7 +905,7 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 			}
 			state = operator.APPLY_VALUE(state, data[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
@@ -3,10 +3,26 @@ package speiger.src.collections.PACKAGE.lists;
 import java.util.Arrays;
 #if TYPE_OBJECT
 import java.util.Comparator;
+#else if !TYPE_BOOLEAN
+import java.util.stream.JAVA_STREAM;
+import java.util.stream.StreamSupport;
 #endif
 import java.util.Collection;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if PRIMITIVES
+import java.util.function.Supplier;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+
+import speiger.src.collections.PACKAGE.utils.COLLECTIONS;
+#endif
+#endif
 #if TYPE_OBJECT
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
@@ -20,6 +36,7 @@ import java.util.function.PREDICATE;
 #if !JDK_FUNCTION
 import java.util.function.JAVA_PREDICATE;
 #endif
+
 import java.util.function.JAVA_UNARY_OPERATOR;
 #endif

@@ -27,6 +44,9 @@ import speiger.src.collections.PACKAGE.collections.COLLECTION;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.PACKAGE.utils.ARRAYS;
 #endif
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
@@ -36,10 +56,6 @@ import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 import speiger.src.collections.objects.utils.ObjectArrays;
 import speiger.src.collections.PACKAGE.utils.ITERATORS;
-#if PRIMITIVES && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
-import java.util.stream.JAVA_STREAM;
-import java.util.stream.StreamSupport;
-#endif
 #if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
 import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
@@ -120,6 +136,42 @@ public class IMMUTABLE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_T
 		data = Arrays.copyOfRange(a, offset, offset+length);
 	}
 	
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a ImmutableList
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, COLLECTION<T>, ImmutableObjectList<T>> toList() {
+		return Collector.of(COLLECTIONS::wrapper, COLLECTION::add, ImmutableObjectList::merge, E -> new IMMUTABLE_LIST<>(E.toArray((T[])new Object[E.size()])));
+	}
+
+	/**
+	 * Collects a Stream to a ImmutableList
+	 * @Type(T)
+	 * @return a list with the contents of the Stream
+	 */
+	public static <T> ImmutableObjectList KEY_GENERIC_TYPE toList(Stream<T> stream) {
+		return stream.collect(toList());
+	}
+	
+	private static <T> COLLECTION<T> merge(COLLECTION<T> a, COLLECTION<T> b) {
+		a.addAll(b);
+		return a;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a ImmutableList
+	 * @return a list with the contents of the Stream
+	 */
+	public static IMMUTABLE_LIST toList(JAVA_STREAM stream) {
+		return new IMMUTABLE_LIST(stream.collect((Supplier<COLLECTION>)COLLECTIONS::wrapper, COLLECTION::add, COLLECTION::addAll).TO_ARRAY());
+	}
+	
+#endif
+#endif
 	@Override
 	public boolean add(KEY_TYPE e) { throw new UnsupportedOperationException(); }
 	@Override
@@ -335,12 +387,12 @@ public class IMMUTABLE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_T
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0,m=data.length;i<m;i++) {
-			if(filter.test(data[i])) return data[i];
+			if(filter.test(data[i])) return OPTIONAL.GET_OPTIONAL(data[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -367,7 +419,7 @@ public class IMMUTABLE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_T

 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -379,7 +431,7 @@ public class IMMUTABLE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_T
 			}
 			state = operator.APPLY_VALUE(state, data[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
@@ -4,7 +4,6 @@ package speiger.src.collections.PACKAGE.lists;
 #if DEQUEUE_FEATURE
 import java.util.Comparator;
 #endif
-
 import java.util.function.BiFunction;
 #else if PRIMITIVES
 import java.nio.JAVA_BUFFER;
@@ -12,12 +11,23 @@ import java.nio.JAVA_BUFFER;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
+#endif
 import java.util.NoSuchElementException;
+#if SPLIT_ITERATOR_FEATURE
 import java.util.Spliterator;
 #if PRIMITIVES
 import java.util.Spliterator.JAVA_SPLIT_ITERATOR;
 #endif
 import java.util.function.Consumer;
+#endif
 import java.util.function.Predicate;
 #if TYPE_OBJECT
 import java.util.function.IntFunction;
@@ -32,6 +42,9 @@ import java.util.function.JAVA_PREDICATE;
 #endif
 import java.util.function.JAVA_UNARY_OPERATOR;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -60,12 +73,14 @@ import speiger.src.collections.objects.utils.ObjectArrays;
 #if TYPE_OBJECT
 import speiger.src.collections.utils.Stack;
 #endif
+#if SPLIT_ITERATOR_FEATURE
 #if PRIMITIVES
 import java.util.stream.JAVA_STREAM;
 import java.util.stream.StreamSupport;
 #endif
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
 import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 import speiger.src.collections.utils.SanityChecks;

 /**
@@ -151,6 +166,42 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 		for(int i = offset,m=offset+length;i<m;add(a[i++]));
 	}
 	
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a LinkedList
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, ObjectLinkedList<T>, ObjectLinkedList<T>> toList() {
+		return Collector.of(ObjectLinkedList::new, ObjectLinkedList::add, ObjectLinkedList::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a LinkedList
+	 * @Type(T)
+	 * @return a list with the contents of the Stream
+	 */
+	public static <T> ObjectLinkedList KEY_GENERIC_TYPE toList(Stream<T> stream) {
+		return stream.collect(ObjectLinkedList::new, ObjectLinkedList::add, ObjectLinkedList::merge);
+	}
+	
+	private ObjectLinkedList<T> merge(ObjectLinkedList<T> a) {
+		addAll(a);
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a LinkedList
+	 * @return a list with the contents of the Stream
+	 */
+	public static LINKED_LIST toList(JAVA_STREAM stream) {
+		return stream.collect(LINKED_LIST::new, LINKED_LIST::add, LINKED_LIST::addAll);
+	}
+	
+#endif
+#endif
 	@Override
 	public boolean add(KEY_TYPE e) {
 		add(size(), e);
@@ -416,6 +467,7 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 		return new ListIter(getNode(index), index);
 	}

+#if SPLIT_ITERATOR_FEATURE
 #if PRIMITIVES
 	/**
 	 * Returns a Java-Type-Specific Stream to reduce boxing/unboxing.
@@ -436,6 +488,7 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 	@Override
 	public SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return new TypeSplitIteratorBRACES(this, first, 0); }
 	
+#endif
 	@Override
 	public void forEach(CONSUMER KEY_SUPER_GENERIC_TYPE action) {
 		Objects.requireNonNull(action);
@@ -487,12 +540,12 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(Entry KEY_GENERIC_TYPE entry = first;entry != null;entry = entry.next) {
-			if(filter.test(entry.value)) return entry.value;
+			if(filter.test(entry.value)) return OPTIONAL.GET_OPTIONAL(entry.value);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -519,7 +572,7 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -531,7 +584,7 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 			}
 			state = operator.APPLY_VALUE(state, entry.value);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
@@ -1253,6 +1306,7 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 		}
 	}
 	
+#if SPLIT_ITERATOR_FEATURE
 	private static class TypeSplitIterator KEY_GENERIC_TYPE implements SPLIT_ITERATOR KEY_GENERIC_TYPE 
 	{
 		static final int BATCH_UNIT = 1 << 10;
@@ -1397,4 +1451,5 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 		}
 	}
 #endif
+#endif
 }
@@ -15,7 +15,10 @@ import java.util.function.UnaryOperator;
 #endif

 import speiger.src.collections.PACKAGE.collections.COLLECTION;
+import speiger.src.collections.PACKAGE.collections.ORDERED_COLLECTION;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
@@ -27,7 +30,9 @@ import speiger.src.collections.PACKAGE.utils.LISTS;
 #if INT_LIST_MODULE && !TYPE_INT
 import speiger.src.collections.ints.lists.IntList;
 #endif
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 #if TYPE_BYTE || TYPE_SHORT || TYPE_CHAR || TYPE_FLOAT
 import speiger.src.collections.utils.SanityChecks;
 #endif
@@ -36,7 +41,7 @@ import speiger.src.collections.utils.SanityChecks;
 * A Type Specific List interface that reduces boxing/unboxing and adds a couple extra quality of life features
 * @Type(T)
 */
-public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List<CLASS_TYPE>
+public interface LIST KEY_GENERIC_TYPE extends ORDERED_COLLECTION KEY_GENERIC_TYPE, List<CLASS_TYPE>
 {
 #if !TYPE_OBJECT
 	/**
@@ -101,6 +106,24 @@ public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List
 	 */
 	public boolean addAll(int index, LIST KEY_GENERIC_TYPE c);
 	
+	/**
+	 * A method to add an element to the start of a list
+	 * @param e that should be added at the start.
+	 */
+	@Override
+	public default void addFirst(KEY_TYPE e) { 
+		add(0, e);
+	}
+	
+	/**
+	 * A method to add an element to the end of a list
+	 * @param e that should be added at the end.
+	 */
+	@Override
+	public default void addLast(KEY_TYPE e) {
+		add(e);
+	}
+	
 	/**
 	 * Helper method that returns the first element of a List.
 	 * This function was introduced due to how annoying it is to get/remove the last element of a list.
@@ -504,9 +527,56 @@ public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List
 	@Override
 	@Deprecated
 	public default boolean add(CLASS_TYPE e) {
-		return COLLECTION.super.add(e);
+		return ORDERED_COLLECTION.super.add(e);
 	}

+#if JAVA_VERSION>=21
+#if !TYPE_OBJECT
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void addFirst(CLASS_TYPE e) {
+		addFirst(OBJ_TO_KEY(e));
+	}
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void addLast(CLASS_TYPE e) {
+		addLast(OBJ_TO_KEY(e));
+	}
+	
+#endif
+	@Override
+	@Deprecated
+	default CLASS_TYPE getFirst() {
+		return KEY_TO_OBJ(GET_FIRST_KEY());
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE getLast() {
+		return KEY_TO_OBJ(GET_LAST_KEY());
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeFirst() {
+		return KEY_TO_OBJ(REMOVE_FIRST_KEY());
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeLast() {
+		return KEY_TO_OBJ(REMOVE_LAST_KEY());
+	}
+	
+#endif
 	/** {@inheritDoc}
 	 * <p>This default implementation delegates to the corresponding type-specific function.
 	 * @deprecated Please use the corresponding type-specific function instead. 
@@ -554,7 +624,7 @@ public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List
 	@Override
 	@Deprecated
 	public default boolean contains(Object o) {
-		return COLLECTION.super.contains(o);
+		return ORDERED_COLLECTION.super.contains(o);
 	}
 	
 	/** {@inheritDoc}
@@ -564,7 +634,7 @@ public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List
 	@Override
 	@Deprecated
 	public default boolean remove(Object o) {
-		return COLLECTION.super.remove(o);
+		return ORDERED_COLLECTION.super.remove(o);
 	}
 	
 	/** {@inheritDoc}
@@ -594,10 +664,12 @@ public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List
 	}
 #endif
 #endif
+#if SPLIT_ITERATOR_FEATURE
 	/**
 	 * A Type Specific Type Splititerator to reduce boxing/unboxing
 	 * @return type specific splititerator
 	 */
 	@Override
 	default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 0); }
+#endif
 }
@@ -14,6 +14,15 @@ import speiger.src.collections.PACKAGE.functions.function.FUNCTION;
 #endif
 import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
+#if ORDERED_MAP_FEATURE
+import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
+import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
+#if !TYPE_OBJECT
+import speiger.src.collections.objects.sets.AbstractObjectSet;
+import speiger.src.collections.objects.sets.ObjectOrderedSet;
+#endif
+#endif
 import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 import speiger.src.collections.PACKAGE.sets.SET;
 #if MAPS_FEATURE
@@ -42,7 +51,7 @@ import speiger.src.collections.utils.SanityChecks;
 */
 public abstract class ABSTRACT_MAP KEY_VALUE_GENERIC_TYPE extends AbstractMap<CLASS_TYPE, CLASS_VALUE_TYPE> implements MAP KEY_VALUE_GENERIC_TYPE
 {
-	protected VALUE_TYPE defaultReturnValue = EMPTY_VALUE;
+	protected VALUE_TYPE defaultReturnValue = INVALID_VALUE;
 	
 	@Override
 	public VALUE_TYPE getDefaultReturnValue() {
@@ -119,7 +128,7 @@ public abstract class ABSTRACT_MAP KEY_VALUE_GENERIC_TYPE extends AbstractMap<CL
 	public void putAll(CLASS_TYPE[] keys, CLASS_VALUE_TYPE[] values, int offset, int size) {
 		SanityChecks.checkArrayCapacity(keys.length, offset, size);
 		SanityChecks.checkArrayCapacity(values.length, offset, size);
-		for(int i = 0;i<size;i++) put(keys[i], values[i]);		
+		for(int i = 0;i<size;i++) put(OBJ_TO_KEY(keys[i]), OBJ_TO_VALUE(values[i]));		
 	}
 	
 #endif
@@ -543,6 +552,132 @@ public abstract class ABSTRACT_MAP KEY_VALUE_GENERIC_TYPE extends AbstractMap<CL
 		return hash;
 	}
 	
+	public static class REVERSED_ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENERIC_TYPE implements ORDERED_MAP KEY_VALUE_GENERIC_TYPE {
+		ORDERED_MAP KEY_VALUE_GENERIC_TYPE map;
+		
+		public REVERSED_ORDERED_MAP(ORDERED_MAP KEY_VALUE_GENERIC_TYPE map) {
+			this.map = map;
+		}
+		@Override
+		public ABSTRACT_MAP KEY_VALUE_GENERIC_TYPE setDefaultReturnValue(VALUE_TYPE v) {
+			map.setDefaultReturnValue(v);
+			return this;
+		}
+		@Override
+		public VALUE_TYPE getDefaultReturnValue() { return map.getDefaultReturnValue(); }
+		@Override
+		public ORDERED_MAP KEY_VALUE_GENERIC_TYPE copy() { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE put(KEY_TYPE key, VALUE_TYPE value) { return map.put(key, value); }
+		@Override
+		public VALUE_TYPE putIfAbsent(KEY_TYPE key, VALUE_TYPE value) { return map.putIfAbsent(key, value); }
+#if VALUE_PRIMITIVES
+		@Override
+		public VALUE_TYPE addTo(KEY_TYPE key, VALUE_TYPE value) { return map.addTo(key, value); }
+		@Override
+		public VALUE_TYPE subFrom(KEY_TYPE key, VALUE_TYPE value) { return map.subFrom(key, value); }
+#endif
+		@Override
+		public VALUE_TYPE REMOVE_VALUE(KEY_TYPE key) { return map.REMOVE_VALUE(key); }
+#if !TYPE_OBJECT || !VALUE_OBJECT
+		@Override
+		public boolean remove(KEY_TYPE key, VALUE_TYPE value) { return map.remove(key, value); }
+#endif
+		@Override
+		public VALUE_TYPE REMOVE_VALUEOrDefault(KEY_TYPE key, VALUE_TYPE defaultValue) { return map.REMOVE_VALUEOrDefault(key, defaultValue); }
+		@Override
+#if TYPE_OBJECT
+		public boolean containsKey(Object key) { return map.containsKey(key); }
+#else
+		public boolean containsKey(KEY_TYPE key) { return map.containsKey(key); }
+#endif
+		@Override
+#if VALUE_OBJECT
+		public boolean containsValue(Object value) { return map.containsValue(value); }
+#else
+		public boolean containsValue(VALUE_TYPE value) { return map.containsValue(value); }
+#endif
+		@Override
+		public boolean replace(KEY_TYPE key, VALUE_TYPE oldValue, VALUE_TYPE newValue) { return map.replace(key, oldValue, newValue); }
+		@Override
+		public VALUE_TYPE replace(KEY_TYPE key, VALUE_TYPE value) { return map.replace(key, value); }
+		@Override
+		public void REPLACE_VALUES(MAP KEY_VALUE_GENERIC_TYPE m) { map.REPLACE_VALUES(m); }
+		@Override
+		public void REPLACE_VALUES(UNARY_OPERATOR KEY_VALUE_GENERIC_TYPE mappingFunction) { map.REPLACE_VALUES(mappingFunction); }
+		@Override
+		public VALUE_TYPE COMPUTE(KEY_TYPE key, UNARY_OPERATOR KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTE(key, mappingFunction); }
+		@Override
+		public VALUE_TYPE COMPUTE_IF_ABSENT(KEY_TYPE key, FUNCTION KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTE_IF_ABSENT(key, mappingFunction); }
+		@Override
+		public VALUE_TYPE SUPPLY_IF_ABSENT(KEY_TYPE key, VALUE_SUPPLIER VALUE_GENERIC_TYPE valueProvider) { return map.SUPPLY_IF_ABSENT(key, valueProvider); }
+		@Override
+		public VALUE_TYPE COMPUTE_IF_PRESENT(KEY_TYPE key, UNARY_OPERATOR KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTE_IF_PRESENT(key, mappingFunction); }
+#if !VALUE_OBJECT
+		@Override
+		public VALUE_TYPE COMPUTENonDefault(KEY_TYPE key, UNARY_OPERATOR KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTENonDefault(key, mappingFunction); }
+		@Override
+		public VALUE_TYPE COMPUTE_IF_ABSENTNonDefault(KEY_TYPE key, FUNCTION KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTE_IF_ABSENTNonDefault(key, mappingFunction); }
+		@Override
+		public VALUE_TYPE SUPPLY_IF_ABSENTNonDefault(KEY_TYPE key, VALUE_SUPPLIER VALUE_GENERIC_TYPE valueProvider) { return map.SUPPLY_IF_ABSENTNonDefault(key, valueProvider); }
+		@Override
+		public VALUE_TYPE COMPUTE_IF_PRESENTNonDefault(KEY_TYPE key, UNARY_OPERATOR KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTE_IF_PRESENTNonDefault(key, mappingFunction); }
+#endif
+		@Override
+		public VALUE_TYPE MERGE(KEY_TYPE key, VALUE_TYPE value, VALUE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE mappingFunction) { return map.MERGE(key, value, mappingFunction); }
+#if !TYPE_OBJECT || !VALUE_OBJECT
+		@Override
+		public VALUE_TYPE getOrDefault(KEY_TYPE key, VALUE_TYPE defaultValue) { return map.getOrDefault(key, defaultValue); }
+#endif
+		@Override
+		public VALUE_TYPE GET_VALUE(KEY_TYPE key) { return map.GET_VALUE(key); }
+		@Override
+		public VALUE_TYPE putAndMoveToFirst(KEY_TYPE key, VALUE_TYPE value) { return map.putAndMoveToLast(key, value); }
+		@Override
+		public VALUE_TYPE putAndMoveToLast(KEY_TYPE key, VALUE_TYPE value) { return map.putAndMoveToFirst(key, value); }
+		@Override
+		public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) { return map.putLast(key, value); }
+		@Override
+		public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) { return map.putFirst(key, value); }
+		@Override
+		public boolean moveToFirst(KEY_TYPE key) { return map.moveToLast(key); }
+		@Override
+		public boolean moveToLast(KEY_TYPE key) { return map.moveToFirst(key); }
+		@Override
+		public VALUE_TYPE getAndMoveToFirst(KEY_TYPE key) { return map.getAndMoveToLast(key); }
+		@Override
+		public VALUE_TYPE getAndMoveToLast(KEY_TYPE key) { return map.getAndMoveToFirst(key); }
+		@Override
+		public KEY_TYPE FIRST_ENTRY_KEY() { return map.LAST_ENTRY_KEY(); }
+		@Override
+		public KEY_TYPE POLL_FIRST_ENTRY_KEY() { return map.POLL_LAST_ENTRY_KEY(); }
+		@Override
+		public KEY_TYPE LAST_ENTRY_KEY() { return map.FIRST_ENTRY_KEY(); }
+		@Override
+		public KEY_TYPE POLL_LAST_ENTRY_KEY() { return map.POLL_FIRST_ENTRY_KEY(); }
+		@Override
+		public VALUE_TYPE FIRST_ENTRY_VALUE() { return map.LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE LAST_ENTRY_VALUE() { return map.FIRST_ENTRY_VALUE(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() { return map.lastEntry(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() { return map.firstEntry(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() { return map.pollLastEntry(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() { return map.pollFirstEntry(); }
+		@Override
+		public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() { return new AbstractObjectSet.ReversedObjectOrderedSet<>(map.ENTRY_SET()); }
+		@Override
+		public ORDERED_SET KEY_GENERIC_TYPE keySet() { return new ABSTRACT_SET.REVERSED_ORDERED_SETBRACES(map.keySet()); }
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() { return map.values().reversed(); }
+		@Override
+		public ORDERED_MAP KEY_VALUE_GENERIC_TYPE reversed() { return map; }
+	}
+
+	
 	/**
 	 * A Simple Type Specific Entry class to reduce boxing/unboxing
 	 * @Type(T)
@@ -4,15 +4,18 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.concurrent.locks.StampedLock;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 import java.util.function.BiFunction;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif

 #if !TYPE_OBJECT
@@ -40,9 +43,12 @@ import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.function.SINGLE_UNARY_OPERATOR;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if!VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 import speiger.src.collections.PACKAGE.maps.abstracts.ABSTRACT_MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.CONCURRENT_MAP;
@@ -78,6 +84,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if VALUE_OBJECT
@@ -839,7 +846,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -863,11 +870,11 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
 			MapEntry entry = new MapEntry();
 			for(int i = 0,m=segments.length;i<m;i++) {
@@ -877,7 +884,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 				try {
 					while(index != -1) {
 						entry.set(index, i);
-						if(filter.test(entry)) return entry;
+						if(filter.test(entry)) return Optional.ofNullable(entry);
 						index = (int)seg.links[index];
 					}
 				}
@@ -885,7 +892,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -1186,7 +1193,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1210,11 +1217,11 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(int i = 0,m=segments.length;i<m;i++) {
 				Segment KEY_VALUE_GENERIC_TYPE seg = segments[i];
@@ -1222,7 +1229,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 				try {
 					int index = seg.firstIndex;
 					while(index != -1){
-						if(filter.test(seg.keys[index])) return seg.keys[index];
+						if(filter.test(seg.keys[index])) return OPTIONAL.GET_OPTIONAL(seg.keys[index]);
 						index = (int)seg.links[index];
 					}
 				}
@@ -1230,7 +1237,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1454,7 +1461,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1478,20 +1485,20 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
 			for(int i = 0,m=segments.length;i<m;i++) {
 				Segment KEY_VALUE_GENERIC_TYPE seg = segments[i];
 				long stamp = seg.readLock();
 				try {
 					int index = seg.firstIndex;
 					while(index != -1){
-						if(filter.test(seg.values[index])) return seg.values[index];
+						if(filter.test(seg.values[index])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(seg.values[index]);
 						index = (int)seg.links[index];
 					}
 				}
@@ -1499,7 +1506,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -4,14 +4,17 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif

 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
@@ -27,6 +30,7 @@ import speiger.src.collections.ints.functions.consumer.IntObjectConsumer;
 import speiger.src.collections.ints.functions.consumer.VALUE_BI_FROM_INT_CONSUMER;
 #endif
 #if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
 #if !TYPE_INT || !SAME_TYPE
@@ -40,7 +44,7 @@ import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
 import speiger.src.collections.PACKAGE.utils.STRATEGY;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ABSTRACT_COLLECTION;
-import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ITERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_UNARY_OPERATOR;
@@ -59,6 +63,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !TYPE_OBJECT
@@ -233,13 +238,13 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 			if(containsNull) {
 				VALUE_TYPE lastValue = values[nullIndex];
 				values[nullIndex] = value;
-				moveToFirstIndex(nullIndex);
+				moveToFirstIndex(nullIndex, false);
 				return lastValue;
 			}
 			values[nullIndex] = value;
 			containsNull = true;
 			onNodeAdded(nullIndex);
-			moveToFirstIndex(nullIndex);
+			moveToFirstIndex(nullIndex, true);
 		}
 		else {
 			int pos = HashUtil.mix(strategy.hashCode(key)) & mask;
@@ -247,7 +252,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 				if(strategy.equals(keys[pos], key)) {
 					VALUE_TYPE lastValue = values[pos];
 					values[pos] = value;
-					moveToFirstIndex(pos);
+					moveToFirstIndex(pos, false);
 					return lastValue;
 				}
 				pos = ++pos & mask;
@@ -255,7 +260,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 			keys[pos] = key;
 			values[pos] = value;
 			onNodeAdded(pos);
-			moveToFirstIndex(pos);
+			moveToFirstIndex(pos, true);
 		}
 		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
 		return getDefaultReturnValue();
@@ -267,13 +272,13 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 			if(containsNull) {
 				VALUE_TYPE lastValue = values[nullIndex];
 				values[nullIndex] = value;
-				moveToLastIndex(nullIndex);
+				moveToLastIndex(nullIndex, false);
 				return lastValue;
 			}
 			values[nullIndex] = value;
 			containsNull = true;
 			onNodeAdded(nullIndex);
-			moveToLastIndex(nullIndex);
+			moveToLastIndex(nullIndex, true);
 		}
 		else {
 			int pos = HashUtil.mix(strategy.hashCode(key)) & mask;
@@ -281,7 +286,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 				if(strategy.equals(keys[pos], key)) {
 					VALUE_TYPE lastValue = values[pos];
 					values[pos] = value;
-					moveToLastIndex(pos);
+					moveToLastIndex(pos, false);
 					return lastValue;
 				}
 				pos = ++pos & mask;
@@ -289,7 +294,55 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 			keys[pos] = key;
 			values[pos] = value;
 			onNodeAdded(pos);
-			moveToLastIndex(pos);
+			moveToLastIndex(pos, true);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+		return getDefaultReturnValue();
+	}
+	
+	@Override
+	public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) {
+		if(strategy.equals(key, EMPTY_KEY_VALUE)) {
+			if(containsNull) return values[nullIndex];
+			values[nullIndex] = value;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToFirstIndex(nullIndex, true);
+		}
+		else {
+			int pos = HashUtil.mix(strategy.hashCode(key)) & mask;
+			while(!strategy.equals(keys[pos], EMPTY_KEY_VALUE)) {
+				if(strategy.equals(keys[pos], key)) return values[pos];
+				pos = ++pos & mask;
+			}
+			keys[pos] = key;
+			values[pos] = value;
+			onNodeAdded(pos);
+			moveToFirstIndex(pos, true);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+		return getDefaultReturnValue();
+	}
+	
+	@Override
+	public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) {
+		if(strategy.equals(key, EMPTY_KEY_VALUE)) {
+			if(containsNull) return values[nullIndex];
+			values[nullIndex] = value;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToLastIndex(nullIndex, true);
+		}
+		else {
+			int pos = HashUtil.mix(strategy.hashCode(key)) & mask;
+			while(!strategy.equals(keys[pos], EMPTY_KEY_VALUE)) {
+				if(strategy.equals(keys[pos], key)) return values[pos];
+				pos = ++pos & mask;
+			}
+			keys[pos] = key;
+			values[pos] = value;
+			onNodeAdded(pos);
+			moveToLastIndex(pos, true);
 		}
 		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
 		return getDefaultReturnValue();
@@ -300,7 +353,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		if(isEmpty() || strategy.equals(FIRST_ENTRY_KEY(), key)) return false;
 		if(strategy.equals(key, EMPTY_KEY_VALUE)) {
 			if(containsNull) {
-				moveToFirstIndex(nullIndex);
+				moveToFirstIndex(nullIndex, false);
 				return true;
 			}
 		}
@@ -308,7 +361,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 			int pos = HashUtil.mix(strategy.hashCode(key)) & mask;
 			while(!strategy.equals(keys[pos], EMPTY_KEY_VALUE)) {
 				if(strategy.equals(keys[pos], key)) {
-					moveToFirstIndex(pos);
+					moveToFirstIndex(pos, false);
 					return true;
 				}
 				pos = ++pos & mask;
@@ -322,7 +375,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		if(isEmpty() || strategy.equals(LAST_ENTRY_KEY(), key)) return false;
 		if(strategy.equals(key, EMPTY_KEY_VALUE)) {
 			if(containsNull) {
-				moveToLastIndex(nullIndex);
+				moveToLastIndex(nullIndex, false);
 				return true;
 			}
 		}
@@ -330,7 +383,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 			int pos = HashUtil.mix(strategy.hashCode(key)) & mask;
 			while(!strategy.equals(keys[pos], EMPTY_KEY_VALUE)) {
 				if(strategy.equals(keys[pos], key)) {
-					moveToLastIndex(pos);
+					moveToLastIndex(pos, false);
 					return true;
 				}
 				pos = ++pos & mask;
@@ -343,7 +396,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	public VALUE_TYPE getAndMoveToFirst(KEY_TYPE key) {
 		int index = findIndex(key);
 		if(index < 0) return getDefaultReturnValue();
-		moveToFirstIndex(index);
+		moveToFirstIndex(index, false);
 		return values[index];
 	}
 	
@@ -351,7 +404,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	public VALUE_TYPE getAndMoveToLast(KEY_TYPE key) {
 		int index = findIndex(key);
 		if(index < 0) return getDefaultReturnValue();
-		moveToLastIndex(index);
+		moveToLastIndex(index, false);
 		return values[index];
 	}
 	
@@ -430,6 +483,52 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		return values[lastIndex];
 	}
 	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[firstIndex], values[firstIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[lastIndex], values[lastIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = firstIndex;
+		onNodeRemoved(pos);
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		if(strategy.equals(result.ENTRY_KEY(), EMPTY_KEY_VALUE)) {
+			containsNull = false;
+			keys[nullIndex] = EMPTY_KEY_VALUE;
+			values[nullIndex] = EMPTY_VALUE;
+		}
+		else shiftKeys(pos);
+		if(nullIndex > minCapacity && size < maxFill / 4 && nullIndex > HashUtil.DEFAULT_MIN_CAPACITY) rehash(nullIndex / 2);
+		return result;
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = lastIndex;
+		onNodeRemoved(pos);
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		if(strategy.equals(result.ENTRY_KEY(), EMPTY_KEY_VALUE)) {
+			containsNull = false;
+			keys[nullIndex] = EMPTY_KEY_VALUE;
+			values[nullIndex] = EMPTY_VALUE;
+		}
+		else shiftKeys(pos);
+		if(nullIndex > minCapacity && size < maxFill / 4 && nullIndex > HashUtil.DEFAULT_MIN_CAPACITY) rehash(nullIndex / 2);
+		return result;
+	}
+	
 	@Override
 	public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 		if(entrySet == null) entrySet = new MapEntrySet();
@@ -443,9 +542,9 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	}
 	
 	@Override
-	public VALUE_COLLECTION VALUE_GENERIC_TYPE values() {
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
 		if(valuesC == null) valuesC = new Values();
-		return valuesC;
+		return (VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE)valuesC;
 	}
 	
 	@Override
@@ -481,8 +580,8 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		containsNull = false;
 	}
 	
-	protected void moveToFirstIndex(int startPos) {
-		if(size == 1 || firstIndex == startPos) return;
+	protected void moveToFirstIndex(int startPos, boolean adding) {
+		if(size == (adding ? 0 : 1) || firstIndex == startPos) return;
 		if(lastIndex == startPos) {
 			lastIndex = (int)(links[startPos] >>> 32);
 			links[lastIndex] |= 0xFFFFFFFFL;
@@ -499,8 +598,8 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		firstIndex = startPos;
 	}
 	
-	protected void moveToLastIndex(int startPos) {
-		if(size == 1 || lastIndex == startPos) return;
+	protected void moveToLastIndex(int startPos, boolean adding) {
+		if(size == (adding ? 0 : 1) || lastIndex == startPos) return;
 		if(firstIndex == startPos) {
 			firstIndex = (int)links[startPos];
 			links[lastIndex] |= 0xFFFFFFFF00000000L;
@@ -614,6 +713,10 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	}
 	
 	private class MapEntrySet extends AbstractObjectSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> implements ORDERED_MAP.FastOrderedSet KEY_VALUE_GENERIC_TYPE {
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -630,24 +733,24 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() {
 			return new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() {
 			return new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 			POLL_FIRST_ENTRY_KEY();
 			return entry;
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 			POLL_LAST_ENTRY_KEY();
 			return entry;
@@ -655,7 +758,12 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() {
-			return new EntryIterator();
+			return new EntryIterator(true);
+		}
+		
+		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() {
+			return new EntryIterator(false);
 		}
 		
 		@Override
@@ -665,7 +773,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> fastIterator() {
-			return new FastEntryIterator();
+			return new FastEntryIterator(true);
 		}
 		
 		@Override
@@ -774,7 +882,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -789,21 +897,21 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 				state = operator.apply(state, new ValueMapEntry(index));
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			MapEntry entry = new MapEntry();
 			int index = firstIndex;
 			while(index != -1) {
 				entry.set(index);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 				index = (int)links[index];
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -901,9 +1009,12 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 			throw new UnsupportedOperationException();
 		}

+		@Override
+		public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }		
 		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
-
 		@Override
 		public boolean addAndMoveToLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }

@@ -919,7 +1030,12 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 		@Override
 		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-			return new KeyIterator();
+			return new KeyIterator(true);
+		}
+		
+		@Override
+		public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+			return new KeyIterator(false);
 		}
 		
 		@Override
@@ -941,22 +1057,22 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		}
 		
 		@Override
-		public KEY_TYPE FIRST_KEY() {
+		public KEY_TYPE GET_FIRST_KEY() {
 			return FIRST_ENTRY_KEY();
 		}
 		
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() {
+		public KEY_TYPE REMOVE_FIRST_KEY() {
 			return POLL_FIRST_ENTRY_KEY();
 		}

 		@Override
-		public KEY_TYPE LAST_KEY() {
+		public KEY_TYPE GET_LAST_KEY() {
 			return LAST_ENTRY_KEY();
 		}

 		@Override
-		public KEY_TYPE POLL_LAST_KEY() {
+		public KEY_TYPE REMOVE_LAST_KEY() {
 			return POLL_LAST_ENTRY_KEY();
 		}
 		
@@ -1056,7 +1172,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1071,19 +1187,19 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 				state = operator.APPLY_KEY_VALUE(state, keys[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_KEY_VALUE;
+			if(size() <= 0) return OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(keys[index])) return keys[index];
+				if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1100,39 +1216,47 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		}
 	}
 	
-	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE {
+	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE implements VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE {
 #if VALUE_OBJECT
 		@Override
 		@Deprecated
-		public boolean contains(Object e) {
-			return containsValue(e);
-		}
-		
+		public boolean contains(Object e) { return containsValue(e); }
 #else
 		@Override
-		public boolean contains(VALUE_TYPE e) {
-			return containsValue(e);
-		}
-		
+		public boolean contains(VALUE_TYPE e) { return containsValue(e); }
 #endif
 		@Override
-		public boolean add(VALUE_TYPE o) {
-			throw new UnsupportedOperationException();
-		}
-
+		public boolean add(VALUE_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
-		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() {
-			return new ValueIterator();
-		}
-		
+		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() { return new ValueIterator(true); }
 		@Override
-		public int size() {
-			return LINKED_CUSTOM_HASH_MAP.this.size();
-		}
-		
+		public int size() { return LINKED_CUSTOM_HASH_MAP.this.size(); }
 		@Override
-		public void clear() {
-			LINKED_CUSTOM_HASH_MAP.this.clear();
+		public void clear() { LINKED_CUSTOM_HASH_MAP.this.clear(); }
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE reversed() { return new VALUE_ABSTRACT_COLLECTION.VALUE_REVERSED_ORDERED_COLLECTIONVALUE_BRACES(this, this::reverseIterator); }
+		private VALUE_ITERATOR VALUE_GENERIC_TYPE reverseIterator() {
+			return new ValueIterator(false);
+		}
+		@Override
+		public void addFirst(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_FIRST_KEY() { return FIRST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_FIRST_KEY() {
+			VALUE_TYPE result = FIRST_ENTRY_VALUE();
+			POLL_FIRST_ENTRY_KEY();
+			return result; 
+		}
+		@Override
+		public VALUE_TYPE VALUE_GET_LAST_KEY() { return LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_LAST_KEY() {
+			VALUE_TYPE result = LAST_ENTRY_VALUE();
+			POLL_LAST_ENTRY_KEY();
+			return result; 
 		}
 		
 		@Override
@@ -1231,7 +1355,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1246,19 +1370,19 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 				state = operator.APPLY_VALUE(state, values[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(values[index])) return values[index];
+				if(filter.test(values[index])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1278,7 +1402,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	private class FastEntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = new MapEntry();
 		
-		public FastEntryIterator() {}
+		public FastEntryIterator(boolean start) { super(start); }
 		public FastEntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1305,7 +1429,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	private class EntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry;
 		
-		public EntryIterator() {}
+		public EntryIterator(boolean start) { super(start); }
 		public EntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1335,7 +1459,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	
 	private class KeyIterator extends MapIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
 		
-		public KeyIterator() {}
+		public KeyIterator(boolean start) { super(start); }
 		public KeyIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1357,7 +1481,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	}
 	
 	private class ValueIterator extends MapIterator implements VALUE_LIST_ITERATOR VALUE_GENERIC_TYPE {
-		public ValueIterator() {}
+		public ValueIterator(boolean start) { super(start); }
 		
 		@Override
 		public VALUE_TYPE VALUE_PREVIOUS() {
@@ -1378,16 +1502,20 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	}
 	
 	private class MapIterator {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
 		int index = 0;
 		
-		MapIterator() {
-			next = firstIndex;
+		MapIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		MapIterator(KEY_TYPE from) {
+			this.forward = true;
 			if(strategy.equals(from, EMPTY_KEY_VALUE)) {
 				if(containsNull) {
 					next = (int) links[nullIndex];
@@ -1415,11 +1543,11 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		}
 		
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}

 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		public int nextIndex() {
@@ -1479,20 +1607,30 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 		public int previousEntry() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = previous;
-			previous = (int)(links[current] >> 32);
-			next = current;
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return current;
 		}
 		
 		public int nextEntry() {
 			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) moveForwards();
+			else moveBackwards();
+			if(index >= 0) index++;
+			return current;
+		}
+		
+		private void moveBackwards() {
+			current = previous;
+			previous = (int)(links[current] >> 32);
+			next = current;
+		}
+		
+		private void moveForwards() {
 			current = next;
 			next = (int)(links[current]);
 			previous = current;
-			if(index >= 0) index++;
-			return current;
 		}
 		
 		private void ensureIndexKnown() {
@@ -5,14 +5,17 @@ import java.util.ConcurrentModificationException;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif

 #if !TYPE_OBJECT
@@ -37,9 +40,12 @@ import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.function.SINGLE_UNARY_OPERATOR;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if !VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 import speiger.src.collections.PACKAGE.maps.abstracts.ABSTRACT_MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
 #if !TYPE_OBJECT
@@ -75,6 +81,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 import speiger.src.collections.objects.collections.ObjectIterator;
@@ -1090,7 +1097,7 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -1107,25 +1114,25 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 				}
 				state = operator.apply(state, new ValueMapEntry(i));
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			MapEntry entry = new MapEntry();
 			if(containsNull) {
 				entry.set(nullIndex);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 			}
 			for(int i = nullIndex-1;i>=0;i--) {
 				if(!strategy.equals(keys[i], EMPTY_KEY_VALUE)) {
 					entry.set(i);
-					if(filter.test(entry)) return entry;
+					if(filter.test(entry)) return Optional.ofNullable(entry);
 				}
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -1331,7 +1338,7 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1348,18 +1355,18 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 				}
 				state = operator.APPLY_KEY_VALUE(state, keys[i]);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_KEY_VALUE;
-			if(containsNull && filter.test(keys[nullIndex])) return keys[nullIndex];
+			if(size() <= 0) return OPTIONAL.empty();
+			if(containsNull && filter.test(keys[nullIndex])) return OPTIONAL.GET_OPTIONAL(keys[nullIndex]);
 			for(int i = nullIndex-1;i>=0;i--) {
-				if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(keys[i])) return keys[i];
+				if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(keys[i])) return OPTIONAL.GET_OPTIONAL(keys[i]);
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1497,7 +1504,7 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1514,18 +1521,18 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 				}
 				state = operator.APPLY_VALUE(state, values[i]);
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
-			if(containsNull && filter.test(values[nullIndex])) return values[nullIndex];
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
+			if(containsNull && filter.test(values[nullIndex])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[nullIndex]);
 			for(int i = nullIndex-1;i>=0;i--) {
-				if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(values[i])) return values[i];
+				if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(values[i])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[i]);
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -4,14 +4,17 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif

 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
@@ -27,6 +30,7 @@ import speiger.src.collections.ints.functions.consumer.IntObjectConsumer;
 import speiger.src.collections.ints.functions.consumer.VALUE_BI_FROM_INT_CONSUMER;
 #endif
 #if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
 #if !TYPE_INT || !SAME_TYPE
@@ -39,7 +43,7 @@ import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
 import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ABSTRACT_COLLECTION;
-import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ITERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_UNARY_OPERATOR;
@@ -58,6 +62,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !TYPE_OBJECT
@@ -210,13 +215,13 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 			if(containsNull) {
 				VALUE_TYPE lastValue = values[nullIndex];
 				values[nullIndex] = value;
-				moveToFirstIndex(nullIndex);
+				moveToFirstIndex(nullIndex, false);
 				return lastValue;
 			}
 			values[nullIndex] = value;
 			containsNull = true;
 			onNodeAdded(nullIndex);
-			moveToFirstIndex(nullIndex);
+			moveToFirstIndex(nullIndex, true);
 		}
 		else {
 			int pos = HashUtil.mix(KEY_TO_HASH(key)) & mask;
@@ -224,7 +229,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 				if(KEY_EQUALS(keys[pos], key)) {
 					VALUE_TYPE lastValue = values[pos];
 					values[pos] = value;
-					moveToFirstIndex(pos);
+					moveToFirstIndex(pos, false);
 					return lastValue;
 				}
 				pos = ++pos & mask;
@@ -232,7 +237,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 			keys[pos] = key;
 			values[pos] = value;
 			onNodeAdded(pos);
-			moveToFirstIndex(pos);
+			moveToFirstIndex(pos, true);
 		}
 		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
 		return getDefaultReturnValue();
@@ -244,13 +249,13 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 			if(containsNull) {
 				VALUE_TYPE lastValue = values[nullIndex];
 				values[nullIndex] = value;
-				moveToLastIndex(nullIndex);
+				moveToLastIndex(nullIndex, false);
 				return lastValue;
 			}
 			values[nullIndex] = value;
 			containsNull = true;
 			onNodeAdded(nullIndex);
-			moveToLastIndex(nullIndex);
+			moveToLastIndex(nullIndex, true);
 		}
 		else {
 			int pos = HashUtil.mix(KEY_TO_HASH(key)) & mask;
@@ -258,7 +263,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 				if(KEY_EQUALS(keys[pos], key)) {
 					VALUE_TYPE lastValue = values[pos];
 					values[pos] = value;
-					moveToLastIndex(pos);
+					moveToLastIndex(pos, false);
 					return lastValue;
 				}
 				pos = ++pos & mask;
@@ -266,7 +271,55 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 			keys[pos] = key;
 			values[pos] = value;
 			onNodeAdded(pos);
-			moveToLastIndex(pos);
+			moveToLastIndex(pos, true);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+		return getDefaultReturnValue();
+	}
+	
+	@Override
+	public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) {
+		if(KEY_EQUALS_NULL(key)) {
+			if(containsNull) return values[nullIndex];
+			values[nullIndex] = value;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToFirstIndex(nullIndex, true);
+		}
+		else {
+			int pos = HashUtil.mix(KEY_TO_HASH(key)) & mask;
+			while(KEY_EQUALS_NOT_NULL(keys[pos])) {
+				if(KEY_EQUALS(keys[pos], key)) return values[pos];
+				pos = ++pos & mask;
+			}
+			keys[pos] = key;
+			values[pos] = value;
+			onNodeAdded(pos);
+			moveToFirstIndex(pos, true);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+		return getDefaultReturnValue();
+	}
+	
+	@Override
+	public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) {
+		if(KEY_EQUALS_NULL(key)) {
+			if(containsNull) return values[nullIndex];
+			values[nullIndex] = value;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToLastIndex(nullIndex, true);
+		}
+		else {
+			int pos = HashUtil.mix(KEY_TO_HASH(key)) & mask;
+			while(KEY_EQUALS_NOT_NULL(keys[pos])) {
+				if(KEY_EQUALS(keys[pos], key)) return values[pos];
+				pos = ++pos & mask;
+			}
+			keys[pos] = key;
+			values[pos] = value;
+			onNodeAdded(pos);
+			moveToLastIndex(pos, true);
 		}
 		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
 		return getDefaultReturnValue();
@@ -277,7 +330,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		if(isEmpty() || KEY_EQUALS(FIRST_ENTRY_KEY(), key)) return false;
 		if(KEY_EQUALS_NULL(key)) {
 			if(containsNull) {
-				moveToFirstIndex(nullIndex);
+				moveToFirstIndex(nullIndex, false);
 				return true;
 			}
 		}
@@ -285,7 +338,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 			int pos = HashUtil.mix(KEY_TO_HASH(key)) & mask;
 			while(KEY_EQUALS_NOT_NULL(keys[pos])) {
 				if(KEY_EQUALS(keys[pos], key)) {
-					moveToFirstIndex(pos);
+					moveToFirstIndex(pos, false);
 					return true;
 				}
 				pos = ++pos & mask;
@@ -299,7 +352,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		if(isEmpty() || KEY_EQUALS(LAST_ENTRY_KEY(), key)) return false;
 		if(KEY_EQUALS_NULL(key)) {
 			if(containsNull) {
-				moveToLastIndex(nullIndex);
+				moveToLastIndex(nullIndex, false);
 				return true;
 			}
 		}
@@ -307,7 +360,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 			int pos = HashUtil.mix(KEY_TO_HASH(key)) & mask;
 			while(KEY_EQUALS_NOT_NULL(keys[pos])) {
 				if(KEY_EQUALS(keys[pos], key)) {
-					moveToLastIndex(pos);
+					moveToLastIndex(pos, false);
 					return true;
 				}
 				pos = ++pos & mask;
@@ -320,7 +373,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	public VALUE_TYPE getAndMoveToFirst(KEY_TYPE key) {
 		int index = findIndex(key);
 		if(index < 0) return getDefaultReturnValue();
-		moveToFirstIndex(index);
+		moveToFirstIndex(index, false);
 		return values[index];
 	}
 	
@@ -328,7 +381,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	public VALUE_TYPE getAndMoveToLast(KEY_TYPE key) {
 		int index = findIndex(key);
 		if(index < 0) return getDefaultReturnValue();
-		moveToLastIndex(index);
+		moveToLastIndex(index, false);
 		return values[index];
 	}
 	
@@ -434,6 +487,52 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		return values[lastIndex];
 	}
 	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[firstIndex], values[firstIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[lastIndex], values[lastIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = firstIndex;
+		onNodeRemoved(pos);
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		if(KEY_EQUALS_NULL(result.ENTRY_KEY())) {
+			containsNull = false;
+			keys[nullIndex] = EMPTY_KEY_VALUE;
+			values[nullIndex] = EMPTY_VALUE;
+		}
+		else shiftKeys(pos);
+		if(nullIndex > minCapacity && size < maxFill / 4 && nullIndex > HashUtil.DEFAULT_MIN_CAPACITY) rehash(nullIndex / 2);
+		return result;
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = lastIndex;
+		onNodeRemoved(pos);
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		if(KEY_EQUALS_NULL(result.ENTRY_KEY())) {
+			containsNull = false;
+			keys[nullIndex] = EMPTY_KEY_VALUE;
+			values[nullIndex] = EMPTY_VALUE;
+		}
+		else shiftKeys(pos);
+		if(nullIndex > minCapacity && size < maxFill / 4 && nullIndex > HashUtil.DEFAULT_MIN_CAPACITY) rehash(nullIndex / 2);
+		return result;
+	}
+	
 	@Override
 	public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 		if(entrySet == null) entrySet = new MapEntrySet();
@@ -447,9 +546,9 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	}
 	
 	@Override
-	public VALUE_COLLECTION VALUE_GENERIC_TYPE values() {
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
 		if(valuesC == null) valuesC = new Values();
-		return valuesC;
+		return (VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE)valuesC;
 	}
 	
 	@Override
@@ -485,8 +584,8 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		containsNull = false;
 	}
 	
-	protected void moveToFirstIndex(int startPos) {
-		if(size == 1 || firstIndex == startPos) return;
+	protected void moveToFirstIndex(int startPos, boolean adding) {
+		if(size == (adding ? 0 : 1) || firstIndex == startPos) return;
 		if(lastIndex == startPos) {
 			lastIndex = (int)(links[startPos] >>> 32);
 			links[lastIndex] |= 0xFFFFFFFFL;
@@ -503,8 +602,8 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		firstIndex = startPos;
 	}
 	
-	protected void moveToLastIndex(int startPos) {
-		if(size == 1 || lastIndex == startPos) return;
+	protected void moveToLastIndex(int startPos, boolean adding) {
+		if(size == (adding ? 0 : 1) || lastIndex == startPos) return;
 		if(firstIndex == startPos) {
 			firstIndex = (int)links[startPos];
 			links[lastIndex] |= 0xFFFFFFFF00000000L;
@@ -618,6 +717,10 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	}
 	
 	private class MapEntrySet extends AbstractObjectSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> implements ORDERED_MAP.FastOrderedSet KEY_VALUE_GENERIC_TYPE {
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -634,24 +737,24 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() {
 			return new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() {
 			return new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 			POLL_FIRST_ENTRY_KEY();
 			return entry;
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 			POLL_LAST_ENTRY_KEY();
 			return entry;
@@ -659,7 +762,12 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() {
-			return new EntryIterator();
+			return new EntryIterator(true);
+		}
+		
+		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() {
+			return new EntryIterator(false);
 		}
 		
 		@Override
@@ -669,7 +777,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> fastIterator() {
-			return new FastEntryIterator();
+			return new FastEntryIterator(true);
 		}
 		
 		@Override
@@ -778,7 +886,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -793,21 +901,21 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 				state = operator.apply(state, new ValueMapEntry(index));
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			MapEntry entry = new MapEntry();
 			int index = firstIndex;
 			while(index != -1) {
 				entry.set(index);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 				index = (int)links[index];
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -900,6 +1008,12 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		@Override
 		public boolean add(KEY_TYPE o) { throw new UnsupportedOperationException(); }

+		@Override
+		public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		
+		@Override
+		public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		
 		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }

@@ -918,7 +1032,12 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 		@Override
 		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-			return new KeyIterator();
+			return new KeyIterator(true);
+		}
+		
+		@Override
+		public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+			return new KeyIterator(false);
 		}
 		
 		@Override
@@ -940,22 +1059,22 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		}
 		
 		@Override
-		public KEY_TYPE FIRST_KEY() {
+		public KEY_TYPE GET_FIRST_KEY() {
 			return FIRST_ENTRY_KEY();
 		}
 		
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() {
+		public KEY_TYPE REMOVE_FIRST_KEY() {
 			return POLL_FIRST_ENTRY_KEY();
 		}

 		@Override
-		public KEY_TYPE LAST_KEY() {
+		public KEY_TYPE GET_LAST_KEY() {
 			return LAST_ENTRY_KEY();
 		}

 		@Override
-		public KEY_TYPE POLL_LAST_KEY() {
+		public KEY_TYPE REMOVE_LAST_KEY() {
 			return POLL_LAST_ENTRY_KEY();
 		}
 		
@@ -1055,7 +1174,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1070,19 +1189,19 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 				state = operator.APPLY_KEY_VALUE(state, keys[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_KEY_VALUE;
+			if(size() <= 0) return OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(keys[index])) return keys[index];
+				if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1099,41 +1218,50 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		}
 	}
 	
-	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE {
+	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE implements VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE {
 #if VALUE_OBJECT
 		@Override
 		@Deprecated
-		public boolean contains(Object e) {
-			return containsValue(e);
-		}
+		public boolean contains(Object e) { return containsValue(e); }
 		
 #else
 		@Override
-		public boolean contains(VALUE_TYPE e) {
-			return containsValue(e);
-		}
+		public boolean contains(VALUE_TYPE e) { return containsValue(e); }
 		
 #endif
 		@Override
-		public boolean add(VALUE_TYPE o) {
-			throw new UnsupportedOperationException();
-		}
-
+		public boolean add(VALUE_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
-		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() {
-			return new ValueIterator();
-		}
-		
+		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() { return new ValueIterator(true); }
 		@Override
-		public int size() {
-			return LINKED_HASH_MAP.this.size();
-		}
-		
+		public int size() { return LINKED_HASH_MAP.this.size(); }
 		@Override
-		public void clear() {
-			LINKED_HASH_MAP.this.clear();
+		public void clear() { LINKED_HASH_MAP.this.clear(); }
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE reversed() { return new VALUE_ABSTRACT_COLLECTION.VALUE_REVERSED_ORDERED_COLLECTIONVALUE_BRACES(this, this::reverseIterator); }
+		private VALUE_ITERATOR VALUE_GENERIC_TYPE reverseIterator() {
+			return new ValueIterator(false);
+		}
+		@Override
+		public void addFirst(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_FIRST_KEY() { return FIRST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_FIRST_KEY() {
+			VALUE_TYPE result = FIRST_ENTRY_VALUE();
+			POLL_FIRST_ENTRY_KEY();
+			return result; 
+		}
+		@Override
+		public VALUE_TYPE VALUE_GET_LAST_KEY() { return LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_LAST_KEY() {
+			VALUE_TYPE result = LAST_ENTRY_VALUE();
+			POLL_LAST_ENTRY_KEY();
+			return result; 
 		}
-		
 		@Override
 		public void forEach(VALUE_CONSUMER VALUE_SUPER_GENERIC_TYPE action) {
 			Objects.requireNonNull(action);
@@ -1231,7 +1359,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1246,19 +1374,19 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 				state = operator.APPLY_VALUE(state, values[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(values[index])) return values[index];
+				if(filter.test(values[index])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1278,7 +1406,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	private class FastEntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = new MapEntry();
 		
-		public FastEntryIterator() {}
+		public FastEntryIterator(boolean start) { super(start); }
 		public FastEntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1305,7 +1433,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	private class EntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry;
 		
-		public EntryIterator() {}
+		public EntryIterator(boolean start) { super(start); }
 		public EntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1335,7 +1463,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	
 	private class KeyIterator extends MapIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
 		
-		public KeyIterator() {}
+		public KeyIterator(boolean start) { super(start); }
 		public KeyIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1357,7 +1485,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	}
 	
 	private class ValueIterator extends MapIterator implements VALUE_LIST_ITERATOR VALUE_GENERIC_TYPE {
-		public ValueIterator() {}
+		public ValueIterator(boolean start) { super(start); }
 		
 		@Override
 		public VALUE_TYPE VALUE_PREVIOUS() {
@@ -1377,13 +1505,16 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	}
 	
 	private class MapIterator {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
 		int index = 0;
 		
-		MapIterator() {
-			next = firstIndex;
+		MapIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		MapIterator(KEY_TYPE from) {
@@ -1414,11 +1545,11 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		}
 		
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}

 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		public int nextIndex() {
@@ -1478,20 +1609,30 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 		public int previousEntry() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = previous;
-			previous = (int)(links[current] >> 32);
-			next = current;
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return current;
 		}
 		
 		public int nextEntry() {
 			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) moveForwards();
+			else moveBackwards();
+			if(index >= 0) index++;
+			return current;
+		}
+		
+		private void moveBackwards() {
+			current = previous;
+			previous = (int)(links[current] >> 32);
+			next = current;
+		}
+		
+		private void moveForwards() {
 			current = next;
 			next = (int)(links[current]);
 			previous = current;
-			if(index >= 0) index++;
-			return current;
 		}
 		
 		private void ensureIndexKnown() {
@@ -5,14 +5,17 @@ import java.util.ConcurrentModificationException;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif

 #if !TYPE_OBJECT
@@ -37,9 +40,12 @@ import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.function.SINGLE_UNARY_OPERATOR;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if !VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 import speiger.src.collections.PACKAGE.maps.abstracts.ABSTRACT_MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
 #if !TYPE_OBJECT
@@ -73,6 +79,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C

 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 import speiger.src.collections.objects.collections.ObjectIterator;
@@ -1049,7 +1056,7 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -1066,25 +1073,25 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 				}
 				state = operator.apply(state, new ValueMapEntry(i));
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			MapEntry entry = new MapEntry();
 			if(containsNull) {
 				entry.set(nullIndex);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 			}
 			for(int i = nullIndex-1;i>=0;i--) {
 				if(KEY_EQUALS_NOT_NULL(keys[i])) {
 					entry.set(i);
-					if(filter.test(entry)) return entry;
+					if(filter.test(entry)) return Optional.ofNullable(entry);
 				}
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -1286,7 +1293,7 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1303,18 +1310,18 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 				}
 				state = operator.APPLY_KEY_VALUE(state, keys[i]);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_KEY_VALUE;
-			if(containsNull && filter.test(keys[nullIndex])) return keys[nullIndex];
+			if(size() <= 0) return OPTIONAL.empty();
+			if(containsNull && filter.test(keys[nullIndex])) return OPTIONAL.GET_OPTIONAL(keys[nullIndex]);
 			for(int i = nullIndex-1;i>=0;i--) {
-				if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(keys[i])) return keys[i];
+				if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(keys[i])) return OPTIONAL.GET_OPTIONAL(keys[i]);
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1452,7 +1459,7 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1469,18 +1476,18 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 				}
 				state = operator.APPLY_VALUE(state, values[i]);
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
-			if(containsNull && filter.test(values[nullIndex])) return values[nullIndex];
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
+			if(containsNull && filter.test(values[nullIndex])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[nullIndex]);
 			for(int i = nullIndex-1;i>=0;i--) {
-				if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(values[i])) return values[i];
+				if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(values[i])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[i]);
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -4,14 +4,17 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif

 #if !TYPE_OBJECT
@@ -26,9 +29,12 @@ import speiger.src.collections.ints.functions.consumer.IntObjectConsumer;
 #if !SAME_TYPE && !TYPE_INT
 import speiger.src.collections.ints.functions.consumer.VALUE_BI_FROM_INT_CONSUMER;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if !VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 #if !TYPE_INT || !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.consumer.BI_CONSUMER;
 #endif
@@ -59,13 +65,14 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 #endif
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ABSTRACT_COLLECTION;
-import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ITERATOR;
 import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_SUPPLIER;
 #if !SAME_TYPE
@@ -119,7 +126,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	/** KeySet cache */
 	protected transient ORDERED_SET KEY_GENERIC_TYPE keySet;
 	/** Values cache */
-	protected transient VALUE_COLLECTION VALUE_GENERIC_TYPE valuesC;
+	protected transient VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE valuesC;
 	
 	/** Amount of Elements stored in the HashMap */
 	protected int size;
@@ -320,6 +327,10 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	@Override
 	public VALUE_TYPE putAndMoveToLast(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
 	@Override
+	public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
+	@Override
+	public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
+	@Override
 	public boolean moveToFirst(KEY_TYPE key) { throw new UnsupportedOperationException(); }
 	@Override
 	public boolean moveToLast(KEY_TYPE key) { throw new UnsupportedOperationException(); }
@@ -443,6 +454,23 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		return values[lastIndex];
 	}
 	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[firstIndex], values[firstIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[lastIndex], values[lastIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() { throw new UnsupportedOperationException(); }
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() { throw new UnsupportedOperationException(); }
+
 	@Override
 	public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 		if(entrySet == null) entrySet = new MapEntrySet();
@@ -456,7 +484,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	}
 	
 	@Override
-	public VALUE_COLLECTION VALUE_GENERIC_TYPE values() {
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
 		if(valuesC == null) valuesC = new Values();
 		return valuesC;
 	}
@@ -609,6 +637,10 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	}
 	
 	private class MapEntrySet extends AbstractObjectSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> implements ORDERED_MAP.FastOrderedSet KEY_VALUE_GENERIC_TYPE {
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -621,24 +653,29 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		public boolean moveToLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() {
 			return new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() {
 			return new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() { throw new UnsupportedOperationException(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() { throw new UnsupportedOperationException(); }
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() { throw new UnsupportedOperationException(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() { throw new UnsupportedOperationException(); }
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() {
-			return new EntryIterator();
+			return new EntryIterator(true);
+		}
+		
+		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() {
+			return new EntryIterator(false);
 		}
 		
 		@Override
@@ -648,7 +685,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> fastIterator() {
-			return new FastEntryIterator();
+			return new FastEntryIterator(true);
 		}
 		
 		@Override
@@ -757,7 +794,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -772,21 +809,21 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 				state = operator.apply(state, new BasicEntryKV_BRACES(keys[index], values[index]));
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES();
 			int index = firstIndex;
 			while(index != -1) {
 				entry.set(keys[index], values[index]);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 				index = (int)links[index];
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -861,6 +898,12 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 			throw new UnsupportedOperationException();
 		}
 		
+		@Override
+		public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		
+		@Override
+		public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		
 		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }

@@ -875,7 +918,12 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		
 		@Override
 		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-			return new KeyIterator();
+			return new KeyIterator(true);
+		}
+		
+		@Override
+		public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+			return new KeyIterator(false);
 		}
 		
 		@Override
@@ -895,20 +943,20 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		public void clear() { throw new UnsupportedOperationException(); }
 		
 		@Override
-		public KEY_TYPE FIRST_KEY() {
+		public KEY_TYPE GET_FIRST_KEY() {
 			return FIRST_ENTRY_KEY();
 		}
 		
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() { throw new UnsupportedOperationException(); }
+		public KEY_TYPE REMOVE_FIRST_KEY() { throw new UnsupportedOperationException(); }

 		@Override
-		public KEY_TYPE LAST_KEY() {
+		public KEY_TYPE GET_LAST_KEY() {
 			return LAST_ENTRY_KEY();
 		}

 		@Override
-		public KEY_TYPE POLL_LAST_KEY() { throw new UnsupportedOperationException(); }
+		public KEY_TYPE REMOVE_LAST_KEY() { throw new UnsupportedOperationException(); }
 		
 		@Override
 		public void forEach(CONSUMER KEY_SUPER_GENERIC_TYPE action) {
@@ -1006,7 +1054,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1021,19 +1069,19 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 				state = operator.APPLY_KEY_VALUE(state, keys[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_KEY_VALUE;
+			if(size() <= 0) return OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(keys[index])) return keys[index];
+				if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1050,39 +1098,42 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		}
 	}
 	
-	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE {
+	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE implements VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE {
 #if VALUE_OBJECT
 		@Override
 		@Deprecated
-		public boolean contains(Object e) {
-			return containsValue(e);
-		}
+		public boolean contains(Object e) { return containsValue(e); }
 		
 #else
 		@Override
-		public boolean contains(VALUE_TYPE e) {
-			return containsValue(e);
-		}
+		public boolean contains(VALUE_TYPE e) { return containsValue(e); }
 		
 #endif
 		@Override
-		public boolean add(VALUE_TYPE o) {
-			throw new UnsupportedOperationException();
-		}
-
+		public boolean add(VALUE_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
-		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() {
-			return new ValueIterator();
-		}
-		
+		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() { return new ValueIterator(true); }
 		@Override
-		public int size() {
-			return IMMUTABLE_HASH_MAP.this.size();
-		}
-		
+		public int size() { return IMMUTABLE_HASH_MAP.this.size(); }
 		@Override
 		public void clear() { throw new UnsupportedOperationException(); }
-		
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE reversed() { return new VALUE_ABSTRACT_COLLECTION.VALUE_REVERSED_ORDERED_COLLECTIONVALUE_BRACES(this, this::reverseIterator); }
+		private VALUE_ITERATOR VALUE_GENERIC_TYPE reverseIterator() {
+			return new ValueIterator(false);
+		}
+		@Override
+		public void addFirst(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_FIRST_KEY() { return FIRST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_FIRST_KEY() { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_LAST_KEY() { return LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_LAST_KEY() { throw new UnsupportedOperationException(); }
 		@Override
 		public void forEach(VALUE_CONSUMER VALUE_SUPER_GENERIC_TYPE action) {
 			int index = firstIndex;
@@ -1179,7 +1230,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1194,19 +1245,19 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 				state = operator.APPLY_VALUE(state, values[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(values[index])) return values[index];
+				if(filter.test(values[index])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1226,7 +1277,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	private class FastEntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = new MapEntry();
 		
-		public FastEntryIterator() {}
+		public FastEntryIterator(boolean start) { super(start); }
 		public FastEntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1252,7 +1303,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	
 	private class EntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		
-		public EntryIterator() {}
+		public EntryIterator(boolean start) { super(start); }
 		public EntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1279,7 +1330,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	
 	private class KeyIterator extends MapIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
 		
-		public KeyIterator() {}
+		public KeyIterator(boolean start) { super(start); }
 		public KeyIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1301,7 +1352,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	}
 	
 	private class ValueIterator extends MapIterator implements VALUE_LIST_ITERATOR VALUE_GENERIC_TYPE {
-		public ValueIterator() {}
+		public ValueIterator(boolean start) { super(start); }
 		
 		@Override
 		public VALUE_TYPE VALUE_PREVIOUS() {
@@ -1322,13 +1373,16 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	}
 	
 	private class MapIterator {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
 		int index = 0;
 		
-		MapIterator() {
-			next = firstIndex;
+		MapIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		MapIterator(KEY_TYPE from) {
@@ -1359,11 +1413,11 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		}
 		
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}

 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		public int nextIndex() {
@@ -1380,20 +1434,30 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		
 		public int previousEntry() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = previous;
-			previous = (int)(links[current] >> 32);
-			next = current;
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return current;
 		}
 		
 		public int nextEntry() {
 			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) moveForwards();
+			else moveBackwards();
+			if(index >= 0) index++;
+			return current;
+		}
+		
+		private void moveBackwards() {
+			current = previous;
+			previous = (int)(links[current] >> 32);
+			next = current;
+		}
+		
+		private void moveForwards() {
 			current = next;
 			next = (int)(links[current]);
 			previous = current;
-			if(index >= 0) index++;
-			return current;
 		}
 		
 		private void ensureIndexKnown() {
@@ -4,14 +4,17 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif

 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
@@ -26,9 +29,12 @@ import speiger.src.collections.ints.functions.consumer.IntObjectConsumer;
 #if !SAME_TYPE && !TYPE_INT
 import speiger.src.collections.ints.functions.consumer.VALUE_BI_FROM_INT_CONSUMER;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if!VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 #if !TYPE_INT || !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.consumer.BI_CONSUMER;
 #endif
@@ -46,7 +52,7 @@ import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
 import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ABSTRACT_COLLECTION;
-import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ITERATOR;
 import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_SUPPLIER;
 #if !SAME_TYPE
@@ -66,6 +72,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !VALUE_OBJECT
@@ -105,7 +112,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	/** KeySet cache */
 	protected ORDERED_SET KEY_GENERIC_TYPE keySet;
 	/** Values cache */
-	protected VALUE_COLLECTION VALUE_GENERIC_TYPE valuesC;
+	protected VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE valuesC;
 	/** EntrySet cache */
 	protected FastOrderedSet KEY_VALUE_GENERIC_TYPE entrySet;
 	
@@ -275,6 +282,27 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		return lastValue;
 	}
 	
+	@Override
+	public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) {
+		int index = findIndex(key);
+		if(index < 0) {
+			insertIndex(0, key, value);
+			size++;
+			return getDefaultReturnValue();
+		}
+		return values[index];
+	}
+	
+	@Override
+	public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) {
+		int index = findIndex(key);
+		if(index < 0) {
+			insertIndex(size++, key, value);
+			return getDefaultReturnValue();
+		}
+		return values[index];
+	}
+	
 	@Override
 	public boolean moveToFirst(KEY_TYPE key) {
 		int index = findIndex(key);
@@ -402,6 +430,34 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		return result;
 	}
 	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[0], values[0]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[size-1], values[size-1]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[0], values[0]);
+		removeIndex(0);
+		return result;
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[size-1], values[size-1]);
+		removeIndex(size-1);
+		return result;
+	}
+	
 	@Override
 	public VALUE_TYPE REMOVE_VALUE(KEY_TYPE key) {
 		int index = findIndex(key);
@@ -461,7 +517,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	}

 	@Override
-	public VALUE_COLLECTION VALUE_GENERIC_TYPE values() {
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
 		if(valuesC == null) valuesC = new Values();
 		return valuesC;
 	}
@@ -812,6 +868,10 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	}
 	
 	private class MapEntrySet extends AbstractObjectSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> implements ORDERED_MAP.FastOrderedSet KEY_VALUE_GENERIC_TYPE {
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -828,24 +888,24 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() {
 			return new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() {
 			return new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 			POLL_FIRST_ENTRY_KEY();
 			return entry;
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 			POLL_LAST_ENTRY_KEY();
 			return entry;
@@ -853,7 +913,12 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() {
-			return new EntryIterator();
+			return new EntryIterator(true);
+		}
+		
+		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() {
+			return new EntryIterator(false);
 		}
 		
 		@Override
@@ -863,7 +928,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> fastIterator() {
-			return new FastEntryIterator();
+			return new FastEntryIterator(true);
 		}
 		
 		@Override
@@ -955,7 +1020,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -967,19 +1032,19 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 				}
 				state = operator.apply(state, new ValueMapEntry(i));
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			MapEntry entry = new MapEntry();
 			for(int i = 0;i<size;i++) {
 				entry.set(i);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -1065,6 +1130,10 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		@Override
 		public boolean add(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
+		public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
@@ -1073,7 +1142,9 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		@Override
 		public boolean moveToLast(KEY_TYPE o) { return ARRAY_MAP.this.moveToLast(o); }
 		@Override
-		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() { return new KeyIterator(); }
+		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() { return new KeyIterator(true); }
+		@Override
+		public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() { return new KeyIterator(false); }
 		@Override
 		public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) { return new KeyIterator(fromElement); } 
 		@Override
@@ -1081,13 +1152,13 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		@Override
 		public void clear() { ARRAY_MAP.this.clear(); }
 		@Override
-		public KEY_TYPE FIRST_KEY() { return FIRST_ENTRY_KEY(); }
+		public KEY_TYPE GET_FIRST_KEY() { return FIRST_ENTRY_KEY(); }
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() { return POLL_FIRST_ENTRY_KEY(); }
+		public KEY_TYPE REMOVE_FIRST_KEY() { return POLL_FIRST_ENTRY_KEY(); }
 		@Override
-		public KEY_TYPE LAST_KEY() { return LAST_ENTRY_KEY(); }
+		public KEY_TYPE GET_LAST_KEY() { return LAST_ENTRY_KEY(); }
 		@Override
-		public KEY_TYPE POLL_LAST_KEY() { return POLL_LAST_ENTRY_KEY(); }
+		public KEY_TYPE REMOVE_LAST_KEY() { return POLL_LAST_ENTRY_KEY(); }
 		
 		@Override
 		public KeySet copy() { throw new UnsupportedOperationException(); }
@@ -1162,7 +1233,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1174,16 +1245,16 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 				}
 				state = operator.APPLY_KEY_VALUE(state, keys[i]);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(int i = 0;i<size;i++) {
-				if(filter.test(keys[i])) return keys[i];
+				if(filter.test(keys[i])) return OPTIONAL.GET_OPTIONAL(keys[i]);
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1197,40 +1268,49 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		}
 	}
 	
-	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE {
+	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE implements VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE {
 #if VALUE_OBJECT
 		@Override
-		public boolean contains(Object e) {
-			return containsValue(e);
-		}
+		public boolean contains(Object e) { return containsValue(e); }
 		
 #else
 		@Override
-		public boolean contains(VALUE_TYPE e) {
-			return containsValue(e);
-		}
+		public boolean contains(VALUE_TYPE e) { return containsValue(e); }
 		
 #endif
 		@Override
-		public boolean add(VALUE_TYPE o) {
-			throw new UnsupportedOperationException();
-		}
-
+		public boolean add(VALUE_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
-		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() {
-			return new ValueIterator();
-		}
-		
+		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() { return new ValueIterator(true); }
 		@Override
-		public int size() {
-			return ARRAY_MAP.this.size();
-		}
-		
+		public int size() { return ARRAY_MAP.this.size(); }
 		@Override
-		public void clear() {
-			ARRAY_MAP.this.clear();
+		public void clear() { ARRAY_MAP.this.clear(); }
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE reversed() { return new VALUE_ABSTRACT_COLLECTION.VALUE_REVERSED_ORDERED_COLLECTIONVALUE_BRACES(this, this::reverseIterator); }
+		private VALUE_ITERATOR VALUE_GENERIC_TYPE reverseIterator() {
+			return new ValueIterator(false);
+		}
+		@Override
+		public void addFirst(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_FIRST_KEY() { return FIRST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_FIRST_KEY() {
+			VALUE_TYPE result = FIRST_ENTRY_VALUE();
+			POLL_FIRST_ENTRY_KEY();
+			return result; 
+		}
+		@Override
+		public VALUE_TYPE VALUE_GET_LAST_KEY() { return LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_LAST_KEY() {
+			VALUE_TYPE result = LAST_ENTRY_VALUE();
+			POLL_LAST_ENTRY_KEY();
+			return result; 
 		}
-		
 		@Override
 		public void forEach(VALUE_CONSUMER VALUE_SUPER_GENERIC_TYPE action) {
 			Objects.requireNonNull(action);
@@ -1294,7 +1374,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1306,16 +1386,16 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 				}
 				state = operator.APPLY_VALUE(state, values[i]);
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(int i = 0;i<size;i++) {
-				if(filter.test(values[i])) return values[i];
+				if(filter.test(values[i])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[i]);
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1332,10 +1412,8 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	private class FastEntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = new MapEntry();
 		
-		public FastEntryIterator() {}
-		public FastEntryIterator(KEY_TYPE from) {
-			index = findIndex(from);
-		}
+		public FastEntryIterator(boolean start) { super(start); }
+		public FastEntryIterator(KEY_TYPE element) { super(element); }
 		
 		@Override
 		public MAP.Entry KEY_VALUE_GENERIC_TYPE next() {
@@ -1358,11 +1436,8 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	private class EntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = null;
 		
-		public EntryIterator() {}
-		public EntryIterator(KEY_TYPE from) {
-			index = findIndex(from);
-			if(index == -1) throw new NoSuchElementException();
-		}
+		public EntryIterator(boolean start) { super(start); }
+		public EntryIterator(KEY_TYPE element) { super(element); }
 		
 		@Override
 		public MAP.Entry KEY_VALUE_GENERIC_TYPE next() {
@@ -1389,11 +1464,8 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	}
 	
 	private class KeyIterator extends MapIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
-		public KeyIterator() {}
-		public KeyIterator(KEY_TYPE element) {
-			index = findIndex(element);
-			if(index == -1) throw new NoSuchElementException();
-		}
+		public KeyIterator(boolean start) { super(start); }
+		public KeyIterator(KEY_TYPE element) { super(element); }
 		
 		@Override
 		public KEY_TYPE PREVIOUS() {
@@ -1413,6 +1485,9 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	}
 	
 	private class ValueIterator extends MapIterator implements VALUE_LIST_ITERATOR VALUE_GENERIC_TYPE {
+		public ValueIterator(boolean start) { super(start); }
+		public ValueIterator(KEY_TYPE element) { super(element); }
+		
 		@Override
 		public VALUE_TYPE VALUE_PREVIOUS() {
 			return values[previousEntry()];
@@ -1431,23 +1506,37 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	}
 	
 	private class MapIterator {
+		boolean forward;
 		int index;
 		int lastReturned = -1;
 		
+		MapIterator(boolean start) {
+			this.forward = start;
+			this.index = start ? 0 : size;
+		}
+		
+		MapIterator(KEY_TYPE element) {
+			this.forward = true;
+			index = findIndex(element);
+			if(index == -1) throw new NoSuchElementException();
+		}
+		
 		public boolean hasNext() {
-			return index < size;
+			return forward ? index < size : index > 0;
 		}
 		
 		public boolean hasPrevious() {
-			return index > 0;
+			return forward ? index > 0 : index < size;
 		}
 		
 		public int nextIndex() {
-			return index;
+			if(forward) return index;
+			return size - index;
 		}
 		
 		public int previousIndex() {
-			return index-1;
+			if(forward) return index-1;
+			return (size - index)-1;
 		}
 		
 		public void remove() {
@@ -1460,26 +1549,42 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		
 		public int previousEntry() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			index--;
-			return (lastReturned = index);
-		}
-		
-		public int nextEntry() {
-			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) {
+				index--;
+				return (lastReturned = index);
+			}
 			lastReturned = index;
 			return index++;
 		}
 		
+		public int nextEntry() {
+			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) {
+				lastReturned = index;
+				return index++;
+			}
+			index--;
+			return (lastReturned = index);
+		}
+		
 		public int skip(int amount) {
 			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+			return forward ? moveForward(amount) : moveBackwards(amount);
+		}
+		
+		public int back(int amount) {
+			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+			return forward ? moveBackwards(amount) : moveForward(amount);
+		}
+		
+		private int moveForward(int amount) {
 			int steps = Math.min(amount, size() - index);
 			index += steps;
 			if(steps > 0) lastReturned = Math.min(index-1, size()-1);
 			return steps;
 		}
 		
-		public int back(int amount) {
-			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+		private int moveBackwards(int amount) {
 			int steps = Math.min(amount, index);
 			index -= steps;
 			if(steps > 0) lastReturned = Math.min(index, size()-1);
@@ -18,7 +18,7 @@ import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
 import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ABSTRACT_COLLECTION;
-import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ITERATOR;
 #if !VALUE_OBJECT && !SAME_TYPE
 import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_CONSUMER;
@@ -216,6 +216,28 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		return getDefaultReturnValue();
 	}
 	
+	@Override
+	public VALUE_TYPE putFirst(T key, VALUE_TYPE value) {
+		int index = key.ordinal();
+		if(isSet(index)) return values[index];
+		set(index);
+		values[index] = value;
+		onNodeAdded(index);
+		moveToFirstIndex(index);
+		return getDefaultReturnValue();
+	}
+	
+	@Override
+	public VALUE_TYPE putLast(T key, VALUE_TYPE value) {
+		int index = key.ordinal();
+		if(isSet(index)) return values[index];
+		set(index);
+		values[index] = value;
+		onNodeAdded(index);
+		moveToLastIndex(index);
+		return getDefaultReturnValue();
+	}
+	
 	@Override
 	public boolean moveToFirst(T key) {
 		int index = key.ordinal();
@@ -312,6 +334,42 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		return values[lastIndex];
 	}
 	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[firstIndex], values[firstIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[lastIndex], values[lastIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = firstIndex;
+		firstIndex = (int)links[pos];
+		if(0 <= firstIndex) links[firstIndex] |= 0xFFFFFFFF00000000L;
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		values[result.ENTRY_KEY().ordinal()] = EMPTY_VALUE;
+		return result;
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = lastIndex;
+		firstIndex = (int)links[pos];
+		if(0 <= firstIndex) links[firstIndex] |= 0xFFFFFFFF00000000L;
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		values[result.ENTRY_KEY().ordinal()] = EMPTY_VALUE;
+		return result;
+	}
+	
 	@Override
 	public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 		if(entrySet == null) entrySet = new MapEntrySet();
@@ -325,9 +383,9 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	}
 	
 	@Override
-	public VALUE_COLLECTION VALUE_GENERIC_TYPE values() {
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
 		if(valuesC == null) valuesC = new Values();
-		return valuesC;
+		return (VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE)valuesC;
 	}
 	
 	@Override
@@ -415,6 +473,10 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	}
 	
 	private class MapEntrySet extends AbstractObjectSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> implements ORDERED_MAP.FastOrderedSet KEY_VALUE_GENERIC_TYPE {
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -431,24 +493,24 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() {
 			return new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() {
 			return new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 			POLL_FIRST_ENTRY_KEY();
 			return entry;
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 			POLL_LAST_ENTRY_KEY();
 			return entry;
@@ -456,7 +518,12 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() {
-			return new EntryIterator();
+			return new EntryIterator(true);
+		}
+		
+		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() {
+			return new EntryIterator(false);
 		}
 		
 		@Override
@@ -466,7 +533,7 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> fastIterator() {
-			return new FastEntryIterator();
+			return new FastEntryIterator(true);
 		}
 		
 		@Override
@@ -574,7 +641,10 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		public boolean add(T o) {
 			throw new UnsupportedOperationException();
 		}
-		
+		@Override
+		public void addFirst(T o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(T o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(T o) { throw new UnsupportedOperationException(); }

@@ -593,7 +663,12 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		
 		@Override
 		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-			return new KeyIterator();
+			return new KeyIterator(true);
+		}
+		
+		@Override
+		public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+			return new KeyIterator(false);
 		}
 		
 		@Override
@@ -614,22 +689,22 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		}
 		
 		@Override
-		public T FIRST_KEY() {
+		public T GET_FIRST_KEY() {
 			return FIRST_ENTRY_KEY();
 		}
 		
 		@Override
-		public T POLL_FIRST_KEY() {
+		public T REMOVE_FIRST_KEY() {
 			return POLL_FIRST_ENTRY_KEY();
 		}

 		@Override
-		public T LAST_KEY() {
+		public T GET_LAST_KEY() {
 			return LAST_ENTRY_KEY();
 		}

 		@Override
-		public T POLL_LAST_KEY() {
+		public T REMOVE_LAST_KEY() {
 			return POLL_LAST_ENTRY_KEY();
 		}
 		
@@ -656,41 +731,50 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 #endif
 	}
 	
-	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE {
+	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE implements VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE {
 #if VALUE_OBJECT
 		@Override
 		@Deprecated
-		public boolean contains(Object e) {
-			return containsValue(e);
-		}
+		public boolean contains(Object e) { return containsValue(e); }
 		
 #else
 		@Override
-		public boolean contains(VALUE_TYPE e) {
-			return containsValue(e);
-		}
+		public boolean contains(VALUE_TYPE e) { return containsValue(e); }
 		
 #endif
 		@Override
-		public boolean add(VALUE_TYPE o) {
-			throw new UnsupportedOperationException();
-		}
-
+		public boolean add(VALUE_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
-		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() {
-			return new ValueIterator();
-		}
-		
+		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() { return new ValueIterator(true); }
 		@Override
-		public int size() {
-			return LINKED_ENUM_MAP.this.size();
-		}
-		
+		public int size() { return LINKED_ENUM_MAP.this.size(); }
 		@Override
-		public void clear() {
-			LINKED_ENUM_MAP.this.clear();
+		public void clear() { LINKED_ENUM_MAP.this.clear(); }
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE reversed() { return new VALUE_ABSTRACT_COLLECTION.VALUE_REVERSED_ORDERED_COLLECTIONVALUE_BRACES(this, this::reverseIterator); }
+		private VALUE_ITERATOR VALUE_GENERIC_TYPE reverseIterator() {
+			return new ValueIterator(false);
+		}
+		@Override
+		public void addFirst(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_FIRST_KEY() { return FIRST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_FIRST_KEY() {
+			VALUE_TYPE result = FIRST_ENTRY_VALUE();
+			POLL_FIRST_ENTRY_KEY();
+			return result; 
+		}
+		@Override
+		public VALUE_TYPE VALUE_GET_LAST_KEY() { return LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_LAST_KEY() {
+			VALUE_TYPE result = LAST_ENTRY_VALUE();
+			POLL_LAST_ENTRY_KEY();
+			return result; 
 		}
-		
 #if VALUE_OBJECT
 		@Override
 		public void forEach(Consumer VALUE_SUPER_GENERIC_TYPE action) {
@@ -715,7 +799,7 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	private class FastEntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = new MapEntry();
 		
-		public FastEntryIterator() {}
+		public FastEntryIterator(boolean start) { super(start); }
 		public FastEntryIterator(T from) {
 			super(from);
 		}
@@ -742,7 +826,7 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	private class EntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry;
 		
-		public EntryIterator() {}
+		public EntryIterator(boolean start) { super(start); }
 		public EntryIterator(T from) {
 			super(from);
 		}
@@ -772,7 +856,7 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	
 	private class KeyIterator extends MapIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
 		
-		public KeyIterator() {}
+		public KeyIterator(boolean start) { super(start); }
 		public KeyIterator(T from) {
 			super(from);
 		}
@@ -794,7 +878,7 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	}
 	
 	private class ValueIterator extends MapIterator implements VALUE_LIST_ITERATOR VALUE_GENERIC_TYPE {
-		public ValueIterator() {}
+		public ValueIterator(boolean start) { super(start); }
 		
 		@Override
 		public VALUE_TYPE VALUE_PREVIOUS() {
@@ -815,16 +899,20 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	}
 	
 	private class MapIterator {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
 		int index = 0;
 		
-		MapIterator() {
-			next = firstIndex;
+		MapIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		MapIterator(T from) {
+			this.forward = true;
 			previous = from.ordinal() - 1;
 			index = from.ordinal();
 			next = from.ordinal();
@@ -832,11 +920,11 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		}
 		
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}

 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		public int nextIndex() {
@@ -871,20 +959,30 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		
 		public int previousEntry() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = previous;
-			previous = (int)(links[current] >> 32);
-			next = current;
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return current;
 		}
 		
 		public int nextEntry() {
 			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) moveForwards();
+			else moveBackwards();
+			if(index >= 0) index++;
+			return current;
+		}
+		
+		private void moveBackwards() {
+			current = previous;
+			previous = (int)(links[current] >> 32);
+			next = current;
+		}
+		
+		private void moveForwards() {
 			current = next;
 			next = (int)(links[current]);
 			previous = current;
-			if(index >= 0) index++;
-			return current;
 		}
 		
 		private void ensureIndexKnown() {
@@ -6,15 +6,18 @@ import java.util.Map;
 import java.util.Comparator;
 #endif
 import java.util.Objects;
+import java.util.Optional;
 import java.util.NoSuchElementException;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif


@@ -37,9 +40,12 @@ import speiger.src.collections.PACKAGE.functions.function.FUNCTION;
 #if !TYPE_INT || !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.consumer.BI_CONSUMER;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if!VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.function.SINGLE_UNARY_OPERATOR;
@@ -73,6 +79,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !TYPE_OBJECT && !VALUE_OBJECT
@@ -1323,7 +1330,7 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1335,15 +1342,15 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 				}
 				state = operator.APPLY_KEY_VALUE(state, entry.key);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Node KEY_VALUE_GENERIC_TYPE entry = start(), end = end();entry != null && (end == null || (end != previous(entry)));entry = next(entry))
-				if(filter.test(entry.key)) return entry.key;
-			return EMPTY_KEY_VALUE;
+				if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -2026,7 +2033,7 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 			}
 			
 			@Override
-			public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+			public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 				Objects.requireNonNull(operator);
 				MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 				boolean empty = true;
@@ -2038,19 +2045,19 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 					}
 					state = operator.apply(state, new BasicEntryKV_BRACES(entry.key, entry.value));
 				}
-				return state;
+				return empty ? Optional.empty() : Optional.ofNullable(state);
 			}
 			
 			@Override
-			public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+			public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 				Objects.requireNonNull(filter);
-				if(size() <= 0) return null;
+				if(size() <= 0) return Optional.empty();
 				BasicEntry KEY_VALUE_GENERIC_TYPE subEntry = new BasicEntryKV_BRACES();
 				for(Node KEY_VALUE_GENERIC_TYPE entry = subLowest(), last = subHighest();entry != null && (last == null || last != previous(entry));entry = next(entry)) {
 					subEntry.set(entry.key, entry.value);
-					if(filter.test(subEntry)) return subEntry;
+					if(filter.test(subEntry)) return Optional.ofNullable(subEntry);
 				}
-				return null;
+				return Optional.empty();
 			}
 			
 			@Override
@@ -2165,7 +2172,7 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 			
 #endif
 			@Override
-			public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+			public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 				Objects.requireNonNull(operator);
 				VALUE_TYPE state = EMPTY_VALUE;
 				boolean empty = true;
@@ -2177,15 +2184,15 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 					}
 					state = operator.APPLY_VALUE(state, entry.value);
 				}
-				return state;
+				return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 			}
 			
 			@Override
-			public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+			public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 				Objects.requireNonNull(filter);
 				for(Node KEY_VALUE_GENERIC_TYPE entry = subLowest(), last = subHighest();entry != null && (last == null || last != previous(entry));entry = next(entry))
-					if(filter.test(entry.value)) return entry.value;
-				return EMPTY_VALUE;
+					if(filter.test(entry.value)) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(entry.value);
+				return VALUE_OPTIONAL.empty();
 			}
 			
 			@Override
@@ -2521,7 +2528,7 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 		
 		#endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -2533,15 +2540,15 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 				}
 				state = operator.APPLY_VALUE(state, entry.value);
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Node KEY_VALUE_GENERIC_TYPE entry = first;entry != null;entry = entry.next())
-				if(filter.test(entry.value)) return entry.value;
-			return EMPTY_VALUE;
+				if(filter.test(entry.value)) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(entry.value);
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -2687,7 +2694,7 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -2699,19 +2706,19 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 				}
 				state = operator.apply(state, new BasicEntryKV_BRACES(entry.key, entry.value));
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			BasicEntry KEY_VALUE_GENERIC_TYPE subEntry = new BasicEntryKV_BRACES();
 			for(Node KEY_VALUE_GENERIC_TYPE entry = first;entry != null;entry = entry.next()) {
 				subEntry.set(entry.key, entry.value);
-				if(filter.test(subEntry)) return subEntry;
+				if(filter.test(subEntry)) return Optional.ofNullable(subEntry);
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -6,15 +6,18 @@ import java.util.Map;
 import java.util.Comparator;
 #endif
 import java.util.Objects;
+import java.util.Optional;
 import java.util.NoSuchElementException;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif

 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
@@ -36,9 +39,12 @@ import speiger.src.collections.PACKAGE.functions.function.FUNCTION;
 #if !TYPE_INT || !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.consumer.BI_CONSUMER;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if!VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.function.SINGLE_UNARY_OPERATOR;
@@ -72,6 +78,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !TYPE_OBJECT && !VALUE_OBJECT
@@ -1379,7 +1386,7 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1391,15 +1398,15 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 				}
 				state = operator.APPLY_KEY_VALUE(state, entry.key);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Node KEY_VALUE_GENERIC_TYPE entry = start(), end = end();entry != null && (end == null || (end != previous(entry)));entry = next(entry))
-				if(filter.test(entry.key)) return entry.key;
-			return EMPTY_KEY_VALUE;
+				if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -2092,7 +2099,7 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 			}
 			
 			@Override
-			public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+			public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 				Objects.requireNonNull(operator);
 				MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 				boolean empty = true;
@@ -2104,19 +2111,19 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 					}
 					state = operator.apply(state, new BasicEntryKV_BRACES(entry.key, entry.value));
 				}
-				return state;
+				return empty ? Optional.empty() : Optional.ofNullable(state);
 			}
 			
 			@Override
-			public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+			public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 				Objects.requireNonNull(filter);
-				if(size() <= 0) return null;
+				if(size() <= 0) return Optional.empty();
 				BasicEntry KEY_VALUE_GENERIC_TYPE subEntry = new BasicEntryKV_BRACES();
 				for(Node KEY_VALUE_GENERIC_TYPE entry = subLowest(), last = subHighest();entry != null && (last == null || last != previous(entry));entry = next(entry)) {
 					subEntry.set(entry.key, entry.value);
-					if(filter.test(subEntry)) return subEntry;
+					if(filter.test(subEntry)) return Optional.ofNullable(subEntry);
 				}
-				return null;
+				return Optional.empty();
 			}
 			
 			@Override
@@ -2231,7 +2238,7 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 			
 #endif
 			@Override
-			public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+			public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 				Objects.requireNonNull(operator);
 				VALUE_TYPE state = EMPTY_VALUE;
 				boolean empty = true;
@@ -2243,15 +2250,15 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 					}
 					state = operator.APPLY_VALUE(state, entry.value);
 				}
-				return state;
+				return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 			}
 			
 			@Override
-			public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+			public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 				Objects.requireNonNull(filter);
 				for(Node KEY_VALUE_GENERIC_TYPE entry = subLowest(), last = subHighest();entry != null && (last == null || last != previous(entry));entry = next(entry))
-					if(filter.test(entry.value)) return entry.value;
-				return EMPTY_VALUE;
+					if(filter.test(entry.value)) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(entry.value);
+				return VALUE_OPTIONAL.empty();
 			}
 			
 			@Override
@@ -2587,7 +2594,7 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 		
 		#endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -2599,15 +2606,15 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 				}
 				state = operator.APPLY_VALUE(state, entry.value);
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Node KEY_VALUE_GENERIC_TYPE entry = first;entry != null;entry = entry.next())
-				if(filter.test(entry.value)) return entry.value;
-			return EMPTY_VALUE;
+				if(filter.test(entry.value)) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(entry.value);
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -2753,7 +2760,7 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -2765,19 +2772,19 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 				}
 				state = operator.apply(state, new BasicEntryKV_BRACES(entry.key, entry.value));
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			BasicEntry KEY_VALUE_GENERIC_TYPE subEntry = new BasicEntryKV_BRACES();
 			for(Node KEY_VALUE_GENERIC_TYPE entry = first;entry != null;entry = entry.next()) {
 				subEntry.set(entry.key, entry.value);
-				if(filter.test(subEntry)) return subEntry;
+				if(filter.test(subEntry)) return Optional.ofNullable(subEntry);
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -154,7 +154,7 @@ public interface MAP KEY_VALUE_GENERIC_TYPE extends Map<CLASS_TYPE, CLASS_VALUE_
 	 * @return the last present value or default return	value.
 	 */
 	public default CLASS_VALUE_TYPE put(Map.Entry<CLASS_TYPE, CLASS_VALUE_TYPE> entry) {
-		return put(entry.getKey(), entry.getValue());
+		return put(OBJ_TO_KEY(entry.getKey()), OBJ_TO_VALUE(entry.getValue()));
 	}

 #endif
@@ -1,8 +1,15 @@
 package speiger.src.collections.PACKAGE.maps.interfaces;

+#if JAVA_VERSION>=21
+import java.util.Map;
+import java.util.SequencedMap;
+
+#endif
 #if MAPS_FEATURE
 import speiger.src.collections.PACKAGE.utils.maps.MAPS;
 #endif
+import speiger.src.collections.PACKAGE.maps.abstracts.ABSTRACT_MAP;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
 #endif
@@ -17,7 +24,11 @@ import speiger.src.collections.objects.sets.ObjectOrderedSet;
 * @Type(T)
 * @ValueType(V)
 */
+#if JAVA_VERSION>=21
+public interface ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends MAP KEY_VALUE_GENERIC_TYPE, SequencedMap<CLASS_TYPE, CLASS_VALUE_TYPE>
+#else
 public interface ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends MAP KEY_VALUE_GENERIC_TYPE
+#endif
 {
 	/**
 	 * A customized put method that allows you to insert into the first index.
@@ -37,6 +48,26 @@ public interface ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends MAP KEY_VALUE_GENERI
 	 */
 	public VALUE_TYPE putAndMoveToLast(KEY_TYPE key, VALUE_TYPE value);
 	
+	/**
+	 * A alternative to putAndMoveToFirst.
+	 * This method simply puts an entry at the first spot of the Map but only if the entry is missing.
+	 * @param key the key that should be inserted
+	 * @param value the value that should be inserted
+	 * @return the previous present or default return value
+	 * @see java.util.Map#put(Object, Object)
+	 */
+	public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value);
+	
+	/**
+	 * A alternative to putAndMoveToLast.
+	 * This method simply puts an entry at the last spot of the Map but only if the entry is missing.
+	 * @param key the key that should be inserted
+	 * @param value the value that should be inserted
+	 * @return the previous present or default return value
+	 * @see java.util.Map#put(Object, Object)
+	 */
+	public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value);
+	
 	/**
 	 * A specific move method to move a given key/value to the first index.
 	 * @param key that should be moved to the first index
@@ -97,13 +128,34 @@ public interface ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends MAP KEY_VALUE_GENERI
 	 */
 	public VALUE_TYPE LAST_ENTRY_VALUE();
 	
+	@Java21
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry();
+	@Java21
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry();
+	@Java21
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry();
+	@Java21
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry();
 	@Override
 	public ORDERED_MAP KEY_VALUE_GENERIC_TYPE copy();
 	@Override
 	public ORDERED_SET KEY_GENERIC_TYPE keySet();
 	@Override
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values();
+	@Override
 	public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET();
+	@Java21
+	public default ORDERED_MAP KEY_VALUE_GENERIC_TYPE reversed() { return new ABSTRACT_MAP.REVERSED_ORDERED_MAPKV_BRACES(this); }
 	
+#if JAVA_VERSION>=21
+	@Override
+	default ORDERED_SET KEY_GENERIC_TYPE sequencedKeySet() { return keySet(); }
+	@Override
+	default VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE sequencedValues() { return values(); }
+	@Override
+	default ObjectOrderedSet<Map.Entry<CLASS_TYPE, CLASS_VALUE_TYPE>> sequencedEntrySet() { return (ObjectOrderedSet<Map.Entry<CLASS_TYPE, CLASS_VALUE_TYPE>>)(Object)ENTRY_SET(); }
+	
+#endif
 #if MAPS_FEATURE
 	/**
 	 * Creates a Wrapped SortedMap that is Synchronized
@@ -130,6 +182,22 @@ public interface ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends MAP KEY_VALUE_GENERI
 	@Override
 	public default ORDERED_MAP KEY_VALUE_GENERIC_TYPE unmodifiable() { return MAPS.unmodifiable(this); }
 	
+#endif
+#if JAVA_VERSION>=21
+#if !SAME_TYPE || !TYPE_OBJECT
+	@Override
+	@Deprecated
+	public default CLASS_VALUE_TYPE putFirst(CLASS_TYPE k, CLASS_VALUE_TYPE v) {
+		return putFirst(OBJ_TO_KEY(k), OBJ_TO_VALUE(v));
+	}
+	
+	@Override
+	@Deprecated
+	public default CLASS_VALUE_TYPE putLast(CLASS_TYPE k, CLASS_VALUE_TYPE v) {
+		return putLast(OBJ_TO_KEY(k), OBJ_TO_VALUE(v));
+	}
+	
+#endif
 #endif
 	/**
 	 * Fast Ordered Entry Set that allows for a faster Entry Iterator by recycling the Entry Object and just exchanging 1 internal value
@@ -7,12 +7,26 @@ import java.util.function.Consumer;
 import java.util.function.BiFunction;
 #endif
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if !TYPE_OBJECT
+import java.util.stream.JAVA_STREAM;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
+#endif
 import java.util.NoSuchElementException;
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif

 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -99,6 +113,47 @@ public class ARRAY_FIFO_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEUE K
 		this(MIN_CAPACITY);
 	}
 	
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a ArrayFIFOQueue
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, ARRAY_FIFO_QUEUE<T>, ARRAY_FIFO_QUEUE<T>> toQueue() {
+		return Collector.of(ARRAY_FIFO_QUEUE::new, ARRAY_FIFO_QUEUE::enqueue, ARRAY_FIFO_QUEUE::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a ArrayFIFOQueue
+	 * @Type(T)
+	 * @return a queue with the contents of the Stream
+	 */
+	public static <T> ARRAY_FIFO_QUEUE KEY_GENERIC_TYPE toQueue(Stream<T> stream) {
+		return stream.collect(ARRAY_FIFO_QUEUE::new, ARRAY_FIFO_QUEUE::enqueue, ARRAY_FIFO_QUEUE::merge);
+	}
+	
+	private ARRAY_FIFO_QUEUE<T> merge(ARRAY_FIFO_QUEUE<T> a) {
+		enqueueAll(a.toArray((T[])new Object[a.size()]));
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a ArrayFIFOQueue
+	 * @return a queue with the contents of the Stream
+	 */
+	public static ARRAY_FIFO_QUEUE toQueue(JAVA_STREAM stream) {
+		return stream.collect(ARRAY_FIFO_QUEUE::new, ARRAY_FIFO_QUEUE::enqueue, ARRAY_FIFO_QUEUE::merge);
+	}
+	
+	private ARRAY_FIFO_QUEUE merge(ARRAY_FIFO_QUEUE a) {
+		enqueueAll(a.TO_ARRAY());
+		return this;
+	}
+	
+#endif
+#endif
 	@Override
 	public ITERATOR KEY_GENERIC_TYPE iterator() {
 		return new Iter();
@@ -318,17 +373,17 @@ public class ARRAY_FIFO_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEUE K
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0,m=size();i<m;i++) {
 			int index = (first + i) % array.length;
 			if(filter.test(array[index])) {
 				KEY_TYPE data = array[index];
 				removeIndex(index);
-				return data;
+				return OPTIONAL.GET_OPTIONAL(data);
 			}
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -355,7 +410,7 @@ public class ARRAY_FIFO_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEUE K
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -367,7 +422,7 @@ public class ARRAY_FIFO_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEUE K
 			}
 			state = operator.APPLY_VALUE(state, array[(first + i) % array.length]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
@@ -8,12 +8,26 @@ import java.util.function.Consumer;
 import java.util.function.BiFunction;
 #endif
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if !TYPE_OBJECT
+import java.util.stream.JAVA_STREAM;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
+#endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif

 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -190,7 +204,47 @@ public class ARRAY_PRIORITY_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUE
 		queue.size = size;
 		return queue;
 	}
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a ArrayPriorityQueue
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, ARRAY_PRIORITY_QUEUE<T>, ARRAY_PRIORITY_QUEUE<T>> toQueue() {
+		return Collector.of(ARRAY_PRIORITY_QUEUE::new, ARRAY_PRIORITY_QUEUE::enqueue, ARRAY_PRIORITY_QUEUE::merge);
+	}
 	
+	/**
+	 * Collects a Stream to a ArrayPriorityQueue
+	 * @Type(T)
+	 * @return a queue with the contents of the Stream
+	 */
+	public static <T> ARRAY_PRIORITY_QUEUE KEY_GENERIC_TYPE toQueue(Stream<T> stream) {
+		return stream.collect(ARRAY_PRIORITY_QUEUE::new, ARRAY_PRIORITY_QUEUE::enqueue, ARRAY_PRIORITY_QUEUE::merge);
+	}
+	
+	private ARRAY_PRIORITY_QUEUE<T> merge(ARRAY_PRIORITY_QUEUE<T> a) {
+		enqueueAll(a.toArray((T[])new Object[a.size()]));
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a ArrayPriorityQueue
+	 * @return a queue with the contents of the Stream
+	 */
+	public static ARRAY_PRIORITY_QUEUE toQueue(JAVA_STREAM stream) {
+		return stream.collect(ARRAY_PRIORITY_QUEUE::new, ARRAY_PRIORITY_QUEUE::enqueue, ARRAY_PRIORITY_QUEUE::merge);
+	}
+	
+	private ARRAY_PRIORITY_QUEUE merge(ARRAY_PRIORITY_QUEUE a) {
+		enqueueAll(a.TO_ARRAY());
+		return this;
+	}
+	
+#endif
+#endif
 	@Override
 	public void enqueue(KEY_TYPE e) {
 		if(size == array.length) array = Arrays.copyOf(array, (int)Math.max(Math.min((long)array.length + (long)(array.length >> 1), (long)SanityChecks.MAX_ARRAY_SIZE), size+1));
@@ -346,7 +400,7 @@ public class ARRAY_PRIORITY_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -358,20 +412,20 @@ public class ARRAY_PRIORITY_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUE
 			}
 			state = operator.APPLY_VALUE(state, array[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0;i<size;i++) {
 			if(filter.test(array[i])) {
 				KEY_TYPE data = array[i];
 				removeIndex(i);
-				return data;
+				return OPTIONAL.GET_OPTIONAL(data);
 			}
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -8,12 +8,26 @@ import java.util.function.Consumer;
 import java.util.function.BiFunction;
 #endif
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if !TYPE_OBJECT
+import java.util.stream.JAVA_STREAM;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
+#endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif

 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -193,6 +207,47 @@ public class HEAP_PRIORITY_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEU
 		return queue;
 	}
 	
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a ArrayFIFOQueue
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, HEAP_PRIORITY_QUEUE<T>, HEAP_PRIORITY_QUEUE<T>> toQueue() {
+		return Collector.of(HEAP_PRIORITY_QUEUE::new, HEAP_PRIORITY_QUEUE::enqueue, HEAP_PRIORITY_QUEUE::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a ArrayFIFOQueue
+	 * @Type(T)
+	 * @return a queue with the contents of the Stream
+	 */
+	public static <T> HEAP_PRIORITY_QUEUE KEY_GENERIC_TYPE toQueue(Stream<T> stream) {
+		return stream.collect(HEAP_PRIORITY_QUEUE::new, HEAP_PRIORITY_QUEUE::enqueue, HEAP_PRIORITY_QUEUE::merge);
+	}
+	
+	private HEAP_PRIORITY_QUEUE<T> merge(HEAP_PRIORITY_QUEUE<T> a) {
+		enqueueAll(a.toArray((T[])new Object[a.size()]));
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a ArrayFIFOQueue
+	 * @return a queue with the contents of the Stream
+	 */
+	public static HEAP_PRIORITY_QUEUE toQueue(JAVA_STREAM stream) {
+		return stream.collect(HEAP_PRIORITY_QUEUE::new, HEAP_PRIORITY_QUEUE::enqueue, HEAP_PRIORITY_QUEUE::merge);
+	}
+	
+	private HEAP_PRIORITY_QUEUE merge(HEAP_PRIORITY_QUEUE a) {
+		enqueueAll(a.TO_ARRAY());
+		return this;
+	}
+	
+#endif
+#endif
 	@Override
 	public int size() {
 		return size;
@@ -326,7 +381,7 @@ public class HEAP_PRIORITY_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEU
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -338,20 +393,20 @@ public class HEAP_PRIORITY_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEU
 			}
 			state = operator.APPLY_VALUE(state, array[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0;i<size;i++) {
 			if(filter.test(array[i])) {
 				KEY_TYPE data = array[i];
 				removeIndex(i);
-				return data;
+				return OPTIONAL.GET_OPTIONAL(data);
 			}
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -10,6 +10,15 @@ import java.util.function.BiFunction;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if !TYPE_OBJECT
+import java.util.stream.JAVA_STREAM;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
@@ -19,6 +28,9 @@ import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -208,6 +220,42 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 		while(iterator.hasNext()) add(iterator.NEXT());
 	}
 	
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a AVLTreeSet
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, AVL_TREE_SET<T>, AVL_TREE_SET<T>> toSet() {
+		return Collector.of(AVL_TREE_SET::new, AVL_TREE_SET::add, AVL_TREE_SET::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a AVLTreeSet
+	 * @Type(T)
+	 * @return a set with the contents of the Stream
+	 */
+	public static <T> AVL_TREE_SET KEY_GENERIC_TYPE toSet(Stream<T> stream) {
+		return stream.collect(AVL_TREE_SET::new, AVL_TREE_SET::add, AVL_TREE_SET::merge);
+	}
+	
+	private AVL_TREE_SET<T> merge(AVL_TREE_SET<T> a) {
+		addAll(a);
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a AVLTreeSet
+	 * @return a set with the contents of the Stream
+	 */
+	public static AVL_TREE_SET toSet(JAVA_STREAM stream) {
+		return stream.collect(AVL_TREE_SET::new, AVL_TREE_SET::add, AVL_TREE_SET::addAll);
+	}
+	
+#endif
+#endif
 #if !TYPE_OBJECT
 	@Override
 	public void setDefaultMaxValue(KEY_TYPE value) { defaultMaxNotFound = value; }
@@ -405,12 +453,12 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(Entry KEY_GENERIC_TYPE entry = first;entry != null;entry = entry.next()) {
-			if(filter.test(entry.key)) return entry.key;
+			if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -437,7 +485,7 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -449,7 +497,7 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 			}
 			state = operator.APPLY_VALUE(state, entry.key);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
@@ -1314,7 +1362,7 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1326,16 +1374,16 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 				}
 				state = operator.APPLY_VALUE(state, entry.key);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Entry KEY_GENERIC_TYPE entry = start();entry != null && inRange(entry.key);entry = next(entry)) {
-				if(filter.test(entry.key)) return entry.key;
+				if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
 			}
-			return EMPTY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -6,6 +6,7 @@ import java.util.Objects;
 import java.util.Set;

 import speiger.src.collections.PACKAGE.collections.ABSTRACT_COLLECTION;
+import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;

 /**
@@ -47,4 +48,105 @@ public abstract class ABSTRACT_SET KEY_GENERIC_TYPE extends ABSTRACT_COLLECTION
 			return false;
 		}
 	}
+	
+#if ORDERED_SET_FEATURE
+	public static class REVERSED_ORDERED_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE implements ORDERED_SET KEY_GENERIC_TYPE {
+		protected ORDERED_SET KEY_GENERIC_TYPE set;
+		
+		public REVERSED_ORDERED_SET(ORDERED_SET KEY_GENERIC_TYPE set) {
+			this.set = set;
+		}
+		
+		@Override
+		public REVERSED_ORDERED_SET KEY_GENERIC_TYPE copy() { throw new UnsupportedOperationException(); }
+		@Override
+		public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) {
+			return set.iterator(fromElement);
+		}
+		
+		@Override
+		public BI_ITERATOR KEY_GENERIC_TYPE iterator() {
+			return set.reverseIterator();
+		}
+		
+		@Override
+		public BI_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+			return set.iterator();
+		}
+		
+		@Override
+		public void addFirst(KEY_TYPE o) {
+			set.addLast(o);
+		}
+		
+		@Override
+		public void addLast(KEY_TYPE o) {
+			set.addFirst(o);
+		}
+		
+		@Override
+#if !TYPE_OBJECT
+		public boolean remove(KEY_TYPE o) {
+#else
+		public boolean remove(Object o) {
+#endif
+			return set.remove(o);
+		}
+		
+		@Override
+		public boolean add(KEY_TYPE o) {
+			return set.add(o);
+		}
+		
+		@Override
+		public boolean addAndMoveToFirst(KEY_TYPE o) {
+			return set.addAndMoveToLast(o);
+		}
+		
+		@Override
+		public boolean addAndMoveToLast(KEY_TYPE o) {
+			return set.addAndMoveToFirst(o);
+		}
+		
+		@Override
+		public boolean moveToFirst(KEY_TYPE o) {
+			return set.moveToLast(o);
+		}
+		
+		@Override
+		public boolean moveToLast(KEY_TYPE o) {
+			return set.moveToFirst(o);
+		}
+		
+		@Override
+		public KEY_TYPE GET_FIRST_KEY() {
+			return set.GET_LAST_KEY();
+		}
+		
+		@Override
+		public KEY_TYPE REMOVE_FIRST_KEY() {
+			return set.REMOVE_LAST_KEY();
+		}
+		
+		@Override
+		public KEY_TYPE GET_LAST_KEY() {
+			return set.GET_FIRST_KEY();
+		}
+		
+		@Override
+		public KEY_TYPE REMOVE_LAST_KEY() {
+			return set.REMOVE_FIRST_KEY();
+		}
+		
+		@Override
+		public ORDERED_SET KEY_GENERIC_TYPE reversed() {
+			return set;
+		}
+		
+		@Override
+		public int size() {
+			return set.size();
+		}
+	}
+#endif
 }
@@ -8,6 +8,15 @@ import java.util.function.BiFunction;
 #endif
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if !TYPE_OBJECT
+import java.util.stream.JAVA_STREAM;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
 import java.util.Set;
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
@@ -18,7 +27,9 @@ import java.util.function.JAVA_PREDICATE;
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
-
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -69,7 +80,7 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	 * @param array the array that should be used for set.
 	 */
 	public ARRAY_SET(KEY_TYPE[] array) {
-		this(array, array.length);
+		this(array, 0, array.length);
 	}
 	
 	/**
@@ -83,6 +94,18 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 		addAll(array, length);
 	}
 	
+	/**
+	 * Constructur using initial Array
+	 * @param array the array that should be used for set.
+	 * @param offset the starting offset of where the array should be copied from
+	 * @param length the amount of elements present within the array
+	 * @throws NegativeArraySizeException if the length is negative
+	 */
+	public ARRAY_SET(KEY_TYPE[] array, int offset, int length) {
+		this(length);
+		addAll(array, offset, length);
+	}
+	
 	/**
 	 * A Helper constructor that allows to create a Set with exactly the same values as the provided collection.
 	 * @param c the elements that should be added to the set.
@@ -126,6 +149,42 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 		for(ITERATOR KEY_GENERIC_TYPE iter = s.iterator();iter.hasNext();data[size++] = iter.NEXT());
 	}
 	
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a ArraySet
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, ARRAY_SET<T>, ARRAY_SET<T>> toList() {
+		return Collector.of(ARRAY_SET::new, ARRAY_SET::add, ARRAY_SET::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a ArraySet
+	 * @Type(T)
+	 * @return a set with the contents of the Stream
+	 */
+	public static <T> ARRAY_SET KEY_GENERIC_TYPE toList(Stream<T> stream) {
+		return stream.collect(ARRAY_SET::new, ARRAY_SET::add, ARRAY_SET::merge);
+	}
+	
+	private ARRAY_SET<T> merge(ARRAY_SET<T> a) {
+		addAll(a);
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a ArraySet
+	 * @return a set with the contents of the Stream
+	 */
+	public static ARRAY_SET toList(JAVA_STREAM stream) {
+		return stream.collect(ARRAY_SET::new, ARRAY_SET::add, ARRAY_SET::addAll);
+	}
+	
+#endif
+#endif
 	@Override
 	public boolean add(KEY_TYPE o) {
 		int index = findIndex(o);
@@ -148,6 +207,25 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	}
 	
 #endif
+	@Override
+	public void addFirst(KEY_TYPE o) {
+		int index = findIndex(o);
+		if(index == -1) {
+			if(data.length == size) data = Arrays.copyOf(data, size == 0 ? 2 : size * 2);
+			System.arraycopy(data, 0, data, 1, size++);
+			data[0] = o;
+		}
+	}
+	
+	@Override
+	public void addLast(KEY_TYPE o) {
+		int index = findIndex(o);
+		if(index == -1) {
+			if(data.length == size) data = Arrays.copyOf(data, size == 0 ? 2 : size * 2);
+			data[size++] = o;
+		}
+	}
+	
 	@Override
 	public boolean addAndMoveToFirst(KEY_TYPE o) {
 		int index = findIndex(o);
@@ -219,13 +297,13 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	
 #endif
 	@Override
-	public KEY_TYPE FIRST_KEY() {
+	public KEY_TYPE GET_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return data[0];
 	}
 	
 	@Override
-	public KEY_TYPE LAST_KEY() {
+	public KEY_TYPE GET_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return data[size - 1];
 	}
@@ -354,7 +432,7 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	
 #endif
 	@Override
-	public KEY_TYPE POLL_FIRST_KEY() {
+	public KEY_TYPE REMOVE_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		KEY_TYPE result = data[0];
 		System.arraycopy(data, 1, data, 0, --size);
@@ -365,7 +443,7 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	}
 	
 	@Override
-	public KEY_TYPE POLL_LAST_KEY() {
+	public KEY_TYPE REMOVE_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		size--;
 #if TYPE_OBJECT
@@ -438,12 +516,12 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0;i<size;i++) {
-			if(filter.test(data[i])) return data[i];
+			if(filter.test(data[i])) return OPTIONAL.GET_OPTIONAL(data[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -470,7 +548,7 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -482,7 +560,7 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 			}
 			state = operator.APPLY_VALUE(state, data[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
@@ -511,13 +589,18 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	
 	@Override
 	public BI_ITERATOR KEY_GENERIC_TYPE iterator() {
-		return new SetIterator(0);
+		return new SetIterator(true, 0);
+	}
+	
+	@Override
+	public BI_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+		return new SetIterator(false, size);
 	}
 	
 	@Override
 	public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) {
 		int index = findIndex(fromElement);
-		if(index != -1) return new SetIterator(index);
+		if(index != -1) return new SetIterator(true, index);
 		throw new NoSuchElementException();
 	}
 	
@@ -570,45 +653,57 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	}
 		
 	private class SetIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
+		boolean forward;
 		int index;
 		int lastReturned = -1;
 		
-		public SetIterator(int index) {
+		public SetIterator(boolean forward, int index) {
+			this.forward = forward;
 			this.index = index;
 		}
 		
 		@Override
 		public boolean hasNext() {
-			return index < size();
+			return forward ? index < size() : index > 0;
 		}
 		
 		@Override
 		public KEY_TYPE NEXT() {
 			if(!hasNext()) throw new NoSuchElementException();
-			lastReturned = index;
-			return data[index++];
+			if(forward) {
+				lastReturned = index;
+				return data[index++];				
+			}
+			index--;
+			return data[(lastReturned = index)];
 		}
 		
 		@Override
 		public boolean hasPrevious() {
-			return index > 0;
+			return forward ? index > 0 : index < size();
 		}
 		
 		@Override
 		public KEY_TYPE PREVIOUS() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			--index;
-			return data[(lastReturned = index)];
+			if(forward) {
+				index--;
+				return data[(lastReturned = index)];
+			}
+			lastReturned = index;
+			return data[index++];
 		}
 		
 		@Override
 		public int nextIndex() {
-			return index;
+			if(forward) return index;
+			return size - index;
 		}
 		
 		@Override
 		public int previousIndex() {
-			return index-1;
+			if(forward) return index-1;
+			return (size - index)-1;
 		}
 		
 		@Override
@@ -637,15 +732,23 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 		@Override
 		public int skip(int amount) {
 			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+			return forward ? moveForward(amount) : moveBackwards(amount);
+		}
+		
+		@Override
+		public int back(int amount) {
+			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+			return forward ? moveBackwards(amount) : moveForward(amount);
+		}
+		
+		private int moveForward(int amount) {
 			int steps = Math.min(amount, size() - index);
 			index += steps;
 			if(steps > 0) lastReturned = Math.min(index-1, size()-1);
 			return steps;
 		}
 		
-		@Override
-		public int back(int amount) {
-			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+		private int moveBackwards(int amount) {
 			int steps = Math.min(amount, index);
 			index -= steps;
 			if(steps > 0) lastReturned = Math.min(index, size()-1);
@@ -9,6 +9,9 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
@@ -19,6 +22,9 @@ import speiger.src.collections.PACKAGE.collections.ITERATOR;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -258,6 +264,10 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 	@Override
 	public boolean addAll(COLLECTION KEY_GENERIC_TYPE c) { throw new UnsupportedOperationException(); }
 	@Override
+	public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+	@Override
+	public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+	@Override
 	public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 	@Override
 	public boolean addAndMoveToLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
@@ -285,22 +295,22 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 	}
 	
 	@Override
-	public KEY_TYPE FIRST_KEY() {
+	public KEY_TYPE GET_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[firstIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_FIRST_KEY() { throw new UnsupportedOperationException(); }
+	public KEY_TYPE REMOVE_FIRST_KEY() { throw new UnsupportedOperationException(); }
 	
 	@Override
-	public KEY_TYPE LAST_KEY() {
+	public KEY_TYPE GET_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[lastIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_LAST_KEY() { throw new UnsupportedOperationException(); }
+	public KEY_TYPE REMOVE_LAST_KEY() { throw new UnsupportedOperationException(); }
 	@Override
 	public boolean remove(Object o) { throw new UnsupportedOperationException(); }

@@ -414,7 +424,7 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -427,18 +437,18 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 			else state = operator.APPLY_VALUE(state, keys[index]);
 			index = (int)links[index];
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		int index = firstIndex;
 		while(index != -1) {
-			if(filter.test(keys[index])) return keys[index];
+			if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 			index = (int)links[index];
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -455,7 +465,12 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 	
 	@Override
 	public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-		return new SetIterator();
+		return new SetIterator(true);
+	}
+	
+	@Override
+	public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+		return new SetIterator(false);
 	}
 	
 	@Override
@@ -521,16 +536,20 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 	}

 	private class SetIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
-		int index = 0;
+		int index = -1;
 		
-		SetIterator() {
-			next = firstIndex;
+		SetIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		SetIterator(KEY_TYPE from) {
+			this.forward = true;
 			if(KEY_EQUALS_NULL(from)) {
 				if(containsNull) {
 					next = (int) links[nullIndex];
@@ -559,48 +578,60 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 		
 		@Override
 		public int skip(int amount) {
-			int result = 0;
-			while(next != -1 && result != amount) {
-				current = previous = next;
-				next = (int)(links[current]);
-				result++;
-			}
+			int result = forward ? moveForward(amount) : moveBackwards(amount);
 			if(index >= 0) index+=result;
 			return result;
 		}
 		
 		@Override
 		public int back(int amount) {
+			int result = forward ? moveBackwards(amount) : moveForward(amount);
+			if(index >= 0) index-=result;
+			return result;
+		}
+		
+		private int moveForward(int amount) {
+			int result = 0;
+			while(next != -1 && result != amount) {
+				current = previous = next;
+				next = (int)(links[current]);
+				result++;
+			}
+			return result;
+		}
+		
+		private int moveBackwards(int amount) {
 			int result = 0;
 			while(previous != -1 && result != amount) {
 				current = next = previous;
 				previous = (int)(links[current] >> 32);
 				result++;
 			}
-			if(index >= 0) index-=result;
 			return result;
 		}
 		
 		@Override
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}

 		@Override
 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		@Override
 		public int nextIndex() {
 			ensureIndexKnown();
-			return index;
+			if(forward) return index;
+			return size - index;
 		}
 		
 		@Override
 		public int previousIndex() {
 			ensureIndexKnown();
-			return index - 1;
+			if(forward) return index-1;
+			return (size - index)-1;
 		}
 		
 		@Override
@@ -609,8 +640,8 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 		@Override
 		public KEY_TYPE PREVIOUS() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = next = previous;
-			previous = (int)(links[current] >> 32);
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return keys[current];
 		}
@@ -618,12 +649,22 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 		@Override
 		public KEY_TYPE NEXT() {
 			if(!hasNext()) throw new NoSuchElementException();
-			current = previous = next;
-			next = (int)(links[current]);
+			if(forward) moveForwards();
+			else moveBackwards();
 			if(index >= 0) index++;
 			return keys[current];
 		}
 		
+		private void moveBackwards() {
+			current = next = previous;
+			previous = (int)(links[current] >> 32);
+		}
+		
+		private void moveForwards() {
+			current = previous = next;
+			next = (int)(links[current]);
+		}
+		
 		private void ensureIndexKnown() {
 			if(index == -1) {
 				if(previous == -1) {
@@ -9,6 +9,15 @@ import java.util.Objects;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if !TYPE_OBJECT
+import java.util.stream.JAVA_STREAM;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
@@ -18,6 +27,9 @@ import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
 #endif
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.PACKAGE.lists.LIST_ITERATOR;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.utils.ITERATORS;
@@ -235,6 +247,82 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	}
 	
 #endif
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a LinkedCustomHashSet
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, LINKED_CUSTOM_HASH_SET<T>, LINKED_CUSTOM_HASH_SET<T>> toLinkedSet(STRATEGY KEY_SUPER_GENERIC_TYPE strategy) {
+		return Collector.of(() -> new LINKED_CUSTOM_HASH_SET<>(strategy), LINKED_CUSTOM_HASH_SET::add, LINKED_CUSTOM_HASH_SET::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a LinkedCustomHashSet
+	 * @Type(T)
+	 * @return a set with the contents of the Stream
+	 */
+	public static <T> LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE toLinkedSet(Stream<T> stream, STRATEGY KEY_SUPER_GENERIC_TYPE strategy) {
+		return stream.collect(() -> new LINKED_CUSTOM_HASH_SET<>(strategy), LINKED_CUSTOM_HASH_SET::add, LINKED_CUSTOM_HASH_SET::merge);
+	}
+	
+	private LINKED_CUSTOM_HASH_SET<T> merge(LINKED_CUSTOM_HASH_SET<T> a) {
+		addAll(a);
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a LinkedCustomHashSet
+	 * @return a set with the contents of the Stream
+	 */
+	public static LINKED_CUSTOM_HASH_SET toList(JAVA_STREAM stream, STRATEGY KEY_SUPER_GENERIC_TYPE strategy) {
+		return stream.collect(() -> new LINKED_CUSTOM_HASH_SET(strategy), LINKED_CUSTOM_HASH_SET::add, LINKED_CUSTOM_HASH_SET::addAll);
+	}
+	
+#endif
+#endif
+	@Override
+	public void addFirst(KEY_TYPE o) {
+		if(strategy.equals(o, EMPTY_KEY_VALUE)) {
+			if(containsNull) return;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToFirstIndex(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(strategy.hashCode(o)) & mask;
+			while(!strategy.equals(keys[pos], EMPTY_KEY_VALUE)) {
+				if(strategy.equals(keys[pos], o)) return;
+				pos = ++pos & mask;
+			}
+			keys[pos] = o;
+			onNodeAdded(pos);
+			moveToFirstIndex(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+	}
+	
+	@Override
+	public void addLast(KEY_TYPE o) {
+		if(strategy.equals(o, EMPTY_KEY_VALUE)) {
+			if(containsNull) return;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(strategy.hashCode(o)) & mask;
+			while(!strategy.equals(keys[pos], EMPTY_KEY_VALUE)) {
+				if(strategy.equals(keys[pos], o)) return;
+				pos = ++pos & mask;
+			}
+			keys[pos] = o;
+			onNodeAdded(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+	}
+	
 	@Override
 	public boolean addAndMoveToFirst(KEY_TYPE o) {
 		if(strategy.equals(o, EMPTY_KEY_VALUE)) {
@@ -291,7 +379,7 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	
 	@Override
 	public boolean moveToFirst(KEY_TYPE o) {
-		if(isEmpty() || strategy.equals(FIRST_KEY(), o)) return false;
+		if(isEmpty() || strategy.equals(GET_FIRST_KEY(), o)) return false;
 		if(strategy.equals(o, EMPTY_KEY_VALUE)) {
 			if(containsNull) {
 				moveToFirstIndex(nullIndex);
@@ -313,7 +401,7 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	
 	@Override
 	public boolean moveToLast(KEY_TYPE o) {
-		if(isEmpty() || strategy.equals(LAST_KEY(), o)) return false;
+		if(isEmpty() || strategy.equals(GET_LAST_KEY(), o)) return false;
 		if(strategy.equals(o, EMPTY_KEY_VALUE)) {
 			if(containsNull) {
 				moveToLastIndex(nullIndex);
@@ -370,13 +458,13 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	}
 	
 	@Override
-	public KEY_TYPE FIRST_KEY() {
+	public KEY_TYPE GET_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[firstIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_FIRST_KEY() {
+	public KEY_TYPE REMOVE_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		int pos = firstIndex;
 		onNodeRemoved(pos);
@@ -392,13 +480,13 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	}
 	
 	@Override
-	public KEY_TYPE LAST_KEY() {
+	public KEY_TYPE GET_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[lastIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_LAST_KEY() {
+	public KEY_TYPE REMOVE_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		int pos = lastIndex;
 		onNodeRemoved(pos);
@@ -656,7 +744,7 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -669,18 +757,18 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 			else state = operator.APPLY_VALUE(state, keys[index]);
 			index = (int)links[index];
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		int index = firstIndex;
 		while(index != -1) {
-			if(filter.test(keys[index])) return keys[index];
+			if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 			index = (int)links[index];
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -697,7 +785,12 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	
 	@Override
 	public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-		return new SetIterator();
+		return new SetIterator(true);
+	}
+	
+	@Override
+	public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+		return new SetIterator(false);
 	}
 	
 	@Override
@@ -722,16 +815,20 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	}
 	
 	private class SetIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
-		int index = 0;
+		int index = -1;
 		
-		SetIterator() {
-			next = firstIndex;
+		SetIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		SetIterator(KEY_TYPE from) {
+			this.forward = true;
 			if(strategy.equals(from, EMPTY_KEY_VALUE)) {
 				if(containsNull) {
 					next = (int) links[nullIndex];
@@ -760,48 +857,60 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 		
 		@Override
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}

 		@Override
 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		@Override
 		public int skip(int amount) {
-			int result = 0;
-			while(next != -1 && result != amount) {
-				current = previous = next;
-				next = (int)(links[current]);
-				result++;
-			}
+			int result = forward ? moveForward(amount) : moveBackwards(amount);
 			if(index >= 0) index+=result;
 			return result;
 		}
 		
 		@Override
 		public int back(int amount) {
+			int result = forward ? moveBackwards(amount) : moveForward(amount);
+			if(index >= 0) index-=result;
+			return result;
+		}
+		
+		private int moveForward(int amount) {
+			int result = 0;
+			while(next != -1 && result != amount) {
+				current = previous = next;
+				next = (int)(links[current]);
+				result++;
+			}
+			return result;
+		}
+		
+		private int moveBackwards(int amount) {
 			int result = 0;
 			while(previous != -1 && result != amount) {
 				current = next = previous;
 				previous = (int)(links[current] >> 32);
 				result++;
 			}
-			if(index >= 0) index-=result;
 			return result;
 		}
 		
 		@Override
 		public int nextIndex() {
 			ensureIndexKnown();
-			return index;
+			if(forward) return index;
+			return size - index;
 		}
 		
 		@Override
 		public int previousIndex() {
 			ensureIndexKnown();
-			return index - 1;
+			if(forward) return index-1;
+			return (size - index)-1;
 		}
 		
 		@Override
@@ -850,8 +959,8 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 		@Override
 		public KEY_TYPE PREVIOUS() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = next = previous;
-			previous = (int)(links[current] >> 32);
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return keys[current];
 		}
@@ -859,12 +968,22 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 		@Override
 		public KEY_TYPE NEXT() {
 			if(!hasNext()) throw new NoSuchElementException();
-			current = previous = next;
-			next = (int)(links[current]);
+			if(forward) moveForwards();
+			else moveBackwards();
 			if(index >= 0) index++;
 			return keys[current];
 		}
 		
+		private void moveBackwards() {
+			current = next = previous;
+			previous = (int)(links[current] >> 32);
+		}
+		
+		private void moveForwards() {
+			current = previous = next;
+			next = (int)(links[current]);
+		}
+		
 		private void ensureIndexKnown() {
 			if(index == -1) {
 				if(previous == -1) {
@@ -5,6 +5,15 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if !TYPE_OBJECT
+import java.util.stream.JAVA_STREAM;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
 #if TYPE_OBJECT
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
@@ -21,6 +30,9 @@ import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -206,6 +218,82 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	}
 	
 #endif
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a LinkedHashSet
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, LINKED_HASH_SET<T>, LINKED_HASH_SET<T>> toLinkedSet() {
+		return Collector.of(LINKED_HASH_SET::new, LINKED_HASH_SET::add, LINKED_HASH_SET::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a LinkedHashSet
+	 * @Type(T)
+	 * @return a set with the contents of the Stream
+	 */
+	public static <T> LINKED_HASH_SET KEY_GENERIC_TYPE toLinkedSet(Stream<T> stream) {
+		return stream.collect(LINKED_HASH_SET::new, LINKED_HASH_SET::add, LINKED_HASH_SET::merge);
+	}
+	
+	private LINKED_HASH_SET<T> merge(LINKED_HASH_SET<T> a) {
+		addAll(a);
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a LinkedHashSet
+	 * @return a set with the contents of the Stream
+	 */
+	public static LINKED_HASH_SET toLinkedSet(JAVA_STREAM stream) {
+		return stream.collect(LINKED_HASH_SET::new, LINKED_HASH_SET::add, LINKED_HASH_SET::addAll);
+	}
+	
+#endif
+#endif
+	@Override
+	public void addFirst(KEY_TYPE o) {
+		if(KEY_EQUALS_NULL(o)) {
+			if(containsNull) return;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToFirstIndex(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(KEY_TO_HASH(o)) & mask;
+			while(KEY_EQUALS_NOT_NULL(keys[pos])) {
+				if(KEY_EQUALS(keys[pos], o)) return;
+				pos = ++pos & mask;
+			}
+			keys[pos] = o;
+			onNodeAdded(pos);
+			moveToFirstIndex(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+	}
+	
+	@Override
+	public void addLast(KEY_TYPE o) {
+		if(KEY_EQUALS_NULL(o)) {
+			if(containsNull) return;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(KEY_TO_HASH(o)) & mask;
+			while(KEY_EQUALS_NOT_NULL(keys[pos])) {
+				if(KEY_EQUALS(keys[pos], o)) return;
+				pos = ++pos & mask;
+			}
+			keys[pos] = o;
+			onNodeAdded(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+	}
+	
 	@Override
 	public boolean addAndMoveToFirst(KEY_TYPE o) {
 		if(KEY_EQUALS_NULL(o)) {
@@ -262,7 +350,7 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	
 	@Override
 	public boolean moveToFirst(KEY_TYPE o) {
-		if(isEmpty() || KEY_EQUALS(FIRST_KEY(), o)) return false;
+		if(isEmpty() || KEY_EQUALS(GET_FIRST_KEY(), o)) return false;
 		if(KEY_EQUALS_NULL(o)) {
 			if(containsNull) {
 				moveToFirstIndex(nullIndex);
@@ -284,7 +372,7 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	
 	@Override
 	public boolean moveToLast(KEY_TYPE o) {
-		if(isEmpty() || KEY_EQUALS(LAST_KEY(), o)) return false;
+		if(isEmpty() || KEY_EQUALS(GET_LAST_KEY(), o)) return false;
 		if(KEY_EQUALS_NULL(o)) {
 			if(containsNull) {
 				moveToLastIndex(nullIndex);
@@ -341,13 +429,13 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	}
 	
 	@Override
-	public KEY_TYPE FIRST_KEY() {
+	public KEY_TYPE GET_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[firstIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_FIRST_KEY() {
+	public KEY_TYPE REMOVE_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		int pos = firstIndex;
 		onNodeRemoved(pos);
@@ -363,13 +451,13 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	}
 	
 	@Override
-	public KEY_TYPE LAST_KEY() {
+	public KEY_TYPE GET_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[lastIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_LAST_KEY() {
+	public KEY_TYPE REMOVE_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		int pos = lastIndex;
 		onNodeRemoved(pos);
@@ -511,7 +599,7 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -524,18 +612,18 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 			else state = operator.APPLY_VALUE(state, keys[index]);
 			index = (int)links[index];
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		int index = firstIndex;
 		while(index != -1) {
-			if(filter.test(keys[index])) return keys[index];
+			if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 			index = (int)links[index];
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -668,7 +756,12 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	
 	@Override
 	public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-		return new SetIterator();
+		return new SetIterator(true);
+	}
+	
+	@Override
+	public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+		return new SetIterator(false);
 	}
 	
 	@Override
@@ -693,16 +786,20 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	}
 	
 	private class SetIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
-		int index = 0;
+		int index = -1;
 		
-		SetIterator() {
-			next = firstIndex;
+		SetIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		SetIterator(KEY_TYPE from) {
+			this.forward = true;
 			if(KEY_EQUALS_NULL(from)) {
 				if(containsNull) {
 					next = (int) links[nullIndex];
@@ -731,48 +828,60 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 		
 		@Override
 		public int skip(int amount) {
-			int result = 0;
-			while(next != -1 && result != amount) {
-				current = previous = next;
-				next = (int)(links[current]);
-				result++;
-			}
+			int result = forward ? moveForward(amount) : moveBackwards(amount);
 			if(index >= 0) index+=result;
 			return result;
 		}
 		
 		@Override
 		public int back(int amount) {
+			int result = forward ? moveBackwards(amount) : moveForward(amount);
+			if(index >= 0) index-=result;
+			return result;
+		}
+		
+		private int moveForward(int amount) {
+			int result = 0;
+			while(next != -1 && result != amount) {
+				current = previous = next;
+				next = (int)(links[current]);
+				result++;
+			}
+			return result;
+		}
+		
+		private int moveBackwards(int amount) {
 			int result = 0;
 			while(previous != -1 && result != amount) {
 				current = next = previous;
 				previous = (int)(links[current] >> 32);
 				result++;
 			}
-			if(index >= 0) index-=result;
 			return result;
 		}
 		
 		@Override
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}

 		@Override
 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		@Override
 		public int nextIndex() {
 			ensureIndexKnown();
-			return index;
+			if(forward) return index;
+			return size - index;
 		}
 		
 		@Override
 		public int previousIndex() {
 			ensureIndexKnown();
-			return index - 1;
+			if(forward) return index-1;
+			return (size - index)-1;
 		}
 		
 		@Override
@@ -821,8 +930,8 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 		@Override
 		public KEY_TYPE PREVIOUS() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = next = previous;
-			previous = (int)(links[current] >> 32);
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return keys[current];
 		}
@@ -830,12 +939,22 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 		@Override
 		public KEY_TYPE NEXT() {
 			if(!hasNext()) throw new NoSuchElementException();
-			current = previous = next;
-			next = (int)(links[current]);
+			if(forward) moveForwards();
+			else moveBackwards();
 			if(index >= 0) index++;
 			return keys[current];
 		}
 		
+		private void moveBackwards() {
+			current = next = previous;
+			previous = (int)(links[current] >> 32);
+		}
+		
+		private void moveForwards() {
+			current = previous = next;
+			next = (int)(links[current]);
+		}
+		
 		private void ensureIndexKnown() {
 			if(index == -1) {
 				if(previous == -1) {
@@ -3,11 +3,13 @@ package speiger.src.collections.PACKAGE.sets;
 import java.util.NavigableSet;

 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 #if SETS_FEATURE
 import speiger.src.collections.PACKAGE.utils.SETS;
 #endif
-import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;

 /**
 * A Type Specific Navigable Set interface with a couple helper methods
@@ -145,6 +147,7 @@ public interface NAVIGABLE_SET KEY_GENERIC_TYPE extends NavigableSet<CLASS_TYPE>
 	public default NAVIGABLE_SET KEY_GENERIC_TYPE unmodifiable() { return SETS.unmodifiable(this); }
 	
 #endif
+#if SPLIT_ITERATOR_FEATURE
 	/**
 	 * A Type Specific Type Splititerator to reduce boxing/unboxing
 	 * @return type specific splititerator
@@ -152,6 +155,7 @@ public interface NAVIGABLE_SET KEY_GENERIC_TYPE extends NavigableSet<CLASS_TYPE>
 	@Override
 	default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 0); }
 	
+#endif
 #if !TYPE_OBJECT
 	@Override
 	@Deprecated
@@ -6,6 +6,15 @@ import java.util.ConcurrentModificationException;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if !TYPE_OBJECT
+import java.util.stream.JAVA_STREAM;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
 #if TYPE_OBJECT
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
@@ -16,6 +25,9 @@ import java.util.function.PREDICATE;

 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.utils.ITERATORS;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -251,6 +263,42 @@ public class CUSTOM_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_T
 		while(iterator.hasNext()) add(iterator.NEXT());
 	}
 	
+#endif
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a CustomHashSet
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, CUSTOM_HASH_SET<T>, CUSTOM_HASH_SET<T>> toSet(STRATEGY KEY_SUPER_GENERIC_TYPE strategy) {
+		return Collector.of(() -> new CUSTOM_HASH_SET<>(strategy), CUSTOM_HASH_SET::add, CUSTOM_HASH_SET::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a CustomHashSet
+	 * @Type(T)
+	 * @return a set with the contents of the Stream
+	 */
+	public static <T> CUSTOM_HASH_SET KEY_GENERIC_TYPE toSet(Stream<T> stream, STRATEGY KEY_SUPER_GENERIC_TYPE strategy) {
+		return stream.collect(() -> new CUSTOM_HASH_SET<>(strategy), CUSTOM_HASH_SET::add, CUSTOM_HASH_SET::merge);
+	}
+	
+	private CUSTOM_HASH_SET<T> merge(CUSTOM_HASH_SET<T> a) {
+		addAll(a);
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a CustomHashSet
+	 * @return a set with the contents of the Stream
+	 */
+	public static CUSTOM_HASH_SET toSet(JAVA_STREAM stream, STRATEGY KEY_SUPER_GENERIC_TYPE strategy) {
+		return stream.collect(() -> new CUSTOM_HASH_SET(strategy), CUSTOM_HASH_SET::add, CUSTOM_HASH_SET::addAll);
+	}
+	
+#endif
 #endif
 	/**
 	 * Helper getter function to get the current strategy
@@ -635,7 +683,7 @@ public class CUSTOM_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_T
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -652,18 +700,18 @@ public class CUSTOM_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_T
 			}
 			state = operator.APPLY_VALUE(state, keys[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
-		if(size() <= 0) return EMPTY_VALUE;
-		if(containsNull && filter.test(keys[nullIndex])) return keys[nullIndex];
+		if(size() <= 0) return OPTIONAL.empty();
+		if(containsNull && filter.test(keys[nullIndex])) return OPTIONAL.GET_OPTIONAL(keys[nullIndex]);
 		for(int i = nullIndex-1;i>=0;i--) {
-			if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(keys[i])) return keys[i];
+			if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(keys[i])) return OPTIONAL.GET_OPTIONAL(keys[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -6,6 +6,15 @@ import java.util.ConcurrentModificationException;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if !TYPE_OBJECT
+import java.util.stream.JAVA_STREAM;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
 #if TYPE_OBJECT
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
@@ -20,6 +29,9 @@ import speiger.src.collections.PACKAGE.collections.ITERATOR;
 import speiger.src.collections.PACKAGE.utils.ITERATORS;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -218,6 +230,42 @@ public class HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE imp
 		while(iterator.hasNext()) add(iterator.NEXT());
 	}
 	
+#endif
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a HashSet
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, HASH_SET<T>, HASH_SET<T>> toSet() {
+		return Collector.of(HASH_SET::new, HASH_SET::add, HASH_SET::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a HashSet
+	 * @Type(T)
+	 * @return a set with the contents of the Stream
+	 */
+	public static <T> HASH_SET KEY_GENERIC_TYPE toSet(Stream<T> stream) {
+		return stream.collect(HASH_SET::new, HASH_SET::add, HASH_SET::merge);
+	}
+	
+	private HASH_SET<T> merge(HASH_SET<T> a) {
+		addAll(a);
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a HashSet
+	 * @return a set with the contents of the Stream
+	 */
+	public static HASH_SET toSet(JAVA_STREAM stream) {
+		return stream.collect(HASH_SET::new, HASH_SET::add, HASH_SET::addAll);
+	}
+	
+#endif
 #endif
 	@Override
 	public boolean add(KEY_TYPE o) {
@@ -498,7 +546,7 @@ public class HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE imp
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -515,18 +563,18 @@ public class HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE imp
 			}
 			state = operator.APPLY_VALUE(state, keys[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
-		if(size() <= 0) return EMPTY_VALUE;
-		if(containsNull && filter.test(keys[nullIndex])) return keys[nullIndex];
+		if(size() <= 0) return OPTIONAL.empty();
+		if(containsNull && filter.test(keys[nullIndex])) return OPTIONAL.GET_OPTIONAL(keys[nullIndex]);
 		for(int i = nullIndex-1;i>=0;i--) {
-			if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(keys[i])) return keys[i];
+			if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(keys[i])) return OPTIONAL.GET_OPTIONAL(keys[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -1,11 +1,19 @@
 package speiger.src.collections.PACKAGE.sets;

+#if JAVA_VERSION>=21
+import java.util.SequencedSet;
+
+#endif
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
+import speiger.src.collections.PACKAGE.collections.ORDERED_COLLECTION;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
+import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET.REVERSED_ORDERED_SET;
 #if SETS_FEATURE
 import speiger.src.collections.PACKAGE.utils.SETS;
 #endif
-import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;

 /**
 * A Special Set Interface giving Access to some really usefull functions
@@ -15,7 +23,11 @@ import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
 * 
 * @Type(T)
 */
-public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE
+#if JAVA_VERSION>=21
+public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE, ORDERED_COLLECTION KEY_GENERIC_TYPE, SequencedSet<CLASS_TYPE>
+#else
+public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE, ORDERED_COLLECTION KEY_GENERIC_TYPE
+#endif
 {
 	/**
 	 * A customized add method that allows you to insert into the first index.
@@ -52,6 +64,7 @@ public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE
 	
 	@Override
 	public BI_ITERATOR KEY_GENERIC_TYPE iterator();
+	public BI_ITERATOR KEY_GENERIC_TYPE reverseIterator();
 	
 	/**
 	 * A type Specific Iterator starting from a given key
@@ -61,6 +74,7 @@ public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE
 	 */
 	public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement);
 	
+#if SPLIT_ITERATOR_FEATURE
 	/**
 	 * A Type Specific Type Splititerator to reduce boxing/unboxing
 	 * @return type specific splititerator
@@ -68,26 +82,80 @@ public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE
 	@Override
 	default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 0); }
 	
+#endif
 	/**
 	 * A method to get the first element in the set
 	 * @return first element in the set
 	 */
-	public KEY_TYPE FIRST_KEY();
+	public KEY_TYPE GET_FIRST_KEY();
 	/**
 	 * A method to get and remove the first element in the set
 	 * @return first element in the set
 	 */
-	public KEY_TYPE POLL_FIRST_KEY();
+	public KEY_TYPE REMOVE_FIRST_KEY();
 	/**
 	 * A method to get the last element in the set
 	 * @return last element in the set
 	 */
-	public KEY_TYPE LAST_KEY();
+	public KEY_TYPE GET_LAST_KEY();
 	/**
 	 * A method to get and remove the last element in the set
 	 * @return last element in the set
 	 */
-	public KEY_TYPE POLL_LAST_KEY();
+	public KEY_TYPE REMOVE_LAST_KEY();
+	
+#if JAVA_VERSION>=21 && !TYPE_OBJECT
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void addFirst(CLASS_TYPE e) { addAndMoveToFirst(OBJ_TO_KEY(e)); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void addLast(CLASS_TYPE e) { addAndMoveToLast(OBJ_TO_KEY(e)); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default CLASS_TYPE getFirst() { return GET_FIRST_KEY(); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default CLASS_TYPE getLast() { return GET_LAST_KEY(); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeFirst() { return REMOVE_FIRST_KEY(); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeLast() { return REMOVE_LAST_KEY(); }
+	
+#endif
+	@Java21
+	public default ORDERED_SET KEY_GENERIC_TYPE reversed() { return new REVERSED_ORDERED_SETBRACES(this); }

 #if SETS_FEATURE
 	/**
@@ -2,6 +2,15 @@ package speiger.src.collections.PACKAGE.sets;

 import java.util.Collection;
 import java.util.Collections;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#if !TYPE_OBJECT
+import java.util.stream.JAVA_STREAM;
+#else
+import java.util.stream.Stream;
+import java.util.stream.Collector;
+#endif
+#endif
 #if TYPE_OBJECT
 import java.util.Comparator;
 import java.util.function.Consumer;
@@ -19,6 +28,9 @@ import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -208,6 +220,42 @@ public class RB_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 		while(iterator.hasNext()) add(iterator.NEXT());
 	}
 	
+#if JDK_TYPE && SPLIT_ITERATOR_FEATURE && STREAM_FEATURE
+#if TYPE_OBJECT
+	/**
+	 * Creates a Collector for a RBTreeSet
+	 * @Type(T)
+	 * @return a collector
+	 */
+	public static <T> Collector<T, RB_TREE_SET<T>, RB_TREE_SET<T>> toSet() {
+		return Collector.of(RB_TREE_SET::new, RB_TREE_SET::add, RB_TREE_SET::merge);
+	}
+	
+	/**
+	 * Collects a Stream to a RBTreeSet
+	 * @Type(T)
+	 * @return a set with the contents of the Stream
+	 */
+	public static <T> RB_TREE_SET KEY_GENERIC_TYPE toSet(Stream<T> stream) {
+		return stream.collect(RB_TREE_SET::new, RB_TREE_SET::add, RB_TREE_SET::merge);
+	}
+	
+	private RB_TREE_SET<T> merge(RB_TREE_SET<T> a) {
+		addAll(a);
+		return this;
+	}
+	
+#else
+	/**
+	 * Collects a Stream to a RBTreeSet
+	 * @return a set with the contents of the Stream
+	 */
+	public static RB_TREE_SET toSet(JAVA_STREAM stream) {
+		return stream.collect(RB_TREE_SET::new, RB_TREE_SET::add, RB_TREE_SET::addAll);
+	}
+	
+#endif
+#endif
 #if !TYPE_OBJECT
 	@Override
 	public void setDefaultMaxValue(KEY_TYPE value) { defaultMaxNotFound = value; }
@@ -427,7 +475,7 @@ public class RB_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -439,16 +487,16 @@ public class RB_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 			}
 			state = operator.APPLY_VALUE(state, entry.key);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(Entry KEY_GENERIC_TYPE entry = first;entry != null;entry = entry.next()) {
-			if(filter.test(entry.key)) return entry.key;
+			if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -1374,7 +1422,7 @@ public class RB_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1386,16 +1434,16 @@ public class RB_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 				}
 				state = operator.APPLY_VALUE(state, entry.key);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Entry KEY_GENERIC_TYPE entry = start();entry != null && inRange(entry.key);entry = next(entry)) {
-				if(filter.test(entry.key)) return entry.key;
+				if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
 			}
-			return EMPTY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -4,11 +4,13 @@ import java.util.Set;

 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 #if SETS_FEATURE
 import speiger.src.collections.PACKAGE.utils.SETS;
 #endif
-import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;


 /**
@@ -88,10 +90,12 @@ public interface SET KEY_GENERIC_TYPE extends Set<CLASS_TYPE>, COLLECTION KEY_GE
 	public default SET KEY_GENERIC_TYPE unmodifiable() { return SETS.unmodifiable(this); }
 	
 #endif
+#if SPLIT_ITERATOR_FEATURE
 	/**
 	 * A Type Specific Type Splititerator to reduce boxing/unboxing
 	 * @return type specific splititerator
 	 */
 	@Override
 	default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 0); }
+#endif
 }
@@ -3,7 +3,9 @@ package speiger.src.collections.PACKAGE.sets;
 import java.util.SortedSet;

 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+#endif
 #if TYPE_OBJECT
 import java.util.Comparator;
 #else
@@ -12,7 +14,9 @@ import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 #if SETS_FEATURE
 import speiger.src.collections.PACKAGE.utils.SETS;
 #endif
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif

 /**
 * A Type Specific SortedSet implementation to reduce boxing/unboxing
@@ -67,6 +71,7 @@ public interface SORTED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE, Sorte
 	public default SORTED_SET KEY_GENERIC_TYPE unmodifiable() { return SETS.unmodifiable(this); }
 	
 #endif
+#if SPLIT_ITERATOR_FEATURE
 	/**
 	 * A Type Specific Type Splititerator to reduce boxing/unboxing
 	 * @return type specific splititerator
@@ -74,6 +79,7 @@ public interface SORTED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE, Sorte
 	@Override
 	default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 0); }
 	
+#endif
 #if !TYPE_OBJECT
 	/**
 	 * A Type Specific SubSet method to reduce boxing/unboxing
@@ -17,6 +17,7 @@ import java.util.function.IntFunction;
 #endif
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
 import speiger.src.collections.utils.SanityChecks;
+import speiger.src.collections.utils.Swapper;

 /**
 * A Helper class for Arrays
@@ -337,6 +338,69 @@ public class ARRAYS
 		return array;
 	}
 	
+	/**
+	 * Simple Shuffle method for Arrays.
+	 * With a Callback for indirect shuffling
+	 * @param array the elements that should be shuffled
+	 * @param swapper the callback on the swaps
+	 * @ArrayType(T)
+	 * @note This uses the SanityChecks#getRandom
+	 * @return the provided sorted array
+	 */
+	public static GENERIC_KEY_BRACES KEY_TYPE[] indirectShuffle(KEY_TYPE[] array, Swapper swapper) {
+		return indirectShuffle(array, SanityChecks.getRandom(), swapper);
+	}
+	
+	/**
+	 * Simple Shuffle method for Arrays.
+	 * With a Callback for indirect shuffling
+	 * @param array the elements that should be shuffled
+	 * @param random the Random Number Generator that should be used for the shuffling
+	 * @param swapper the callback on the swaps
+	 * @ArrayType(T)
+	 * @return the provided sorted array
+	 */
+	public static GENERIC_KEY_BRACES KEY_TYPE[] indirectShuffle(KEY_TYPE[] array, RANDOM random, Swapper swapper) {
+		return indirectShuffle(array, 0, array.length, random, swapper);
+	}
+	
+	/**
+	 * Simple Shuffle method for Arrays.
+	 * With a Callback for indirect shuffling
+	 * @param array the elements that should be shuffled
+	 * @param length the length of the array
+	 * @param random the Random Number Generator that should be used for the shuffling
+	 * @param swapper the callback on the swaps
+	 * @ArrayType(T)
+	 * @return the provided sorted array
+	 */
+	public static GENERIC_KEY_BRACES KEY_TYPE[] indirectShuffle(KEY_TYPE[] array, int length, RANDOM random, Swapper swapper) {
+		return indirectShuffle(array, 0, length, random, swapper);
+	}
+	
+	/**
+	 * Simple Shuffle method for Arrays.
+	 * With a Callback for indirect shuffling
+	 * @param array the elements that should be shuffled
+	 * @param offset the start array
+	 * @param length the length of the array
+	 * @param random the Random Number Generator that should be used for the shuffling
+	 * @param swapper the callback on the swaps
+	 * @ArrayType(T)
+	 * @return the provided sorted array
+	 */
+	public static GENERIC_KEY_BRACES KEY_TYPE[] indirectShuffle(KEY_TYPE[] array, int offset, int length, RANDOM random, Swapper swapper) {
+		for(int i = length-1; i>=0;i--) {
+			int j = offset + i;
+			int p = offset + random.nextInt(i + 1);
+			swapper.swap(j, p);
+			KEY_TYPE t = array[j];
+			array[j] = array[p];
+			array[p] = t;
+		}
+		return array;
+	}
+	
 	/**
 	 * Simple Array Reversal method
 	 * @param array the Array that should flip
@@ -575,6 +639,55 @@ public class ARRAYS
 		}
 	}
 	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Insertion Sort,
+	 * On top of that allows to sort other things along with it.
+	 * @param array the array that needs to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 * @return input array
+	 */
+	public static GENERIC_KEY_BRACES KEY_TYPE[] indirectInsertionSort(KEY_TYPE[] array, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectInsertionSort(array, 0, array.length, comp, swapper);
+		return array;
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Insertion Sort,
+	 * On top of that allows to sort other things along with it.
+	 * @param array the array that needs to be sorted
+	 * @param length the maxmium size of the array to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectInsertionSort(KEY_TYPE[] array, int length, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectInsertionSort(array, 0, length, comp, swapper);
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Insertion Sort,
+	 * On top of that allows to sort other things along with it.
+	 * @param array the array that needs to be sorted
+	 * @param from where the array should be sorted from
+	 * @param to where the array should be sorted to
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectInsertionSort(KEY_TYPE[] array, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		for (int i = from+1;i<to; i++) {
+			KEY_TYPE current = array[i];
+			int j = i - 1;
+			while(j >= from && comp.compare(current, array[j]) < 0) {
+				swapper.swap(j+1, j);
+				array[j+1] = array[j--];
+			}
+			array[j+1] = current;
+		}
+	}
+	
 	/**
 	 * Sorts an array according to the natural ascending order using InsertionSort, 
 	 * @param array the array that needs to be sorted
@@ -661,6 +774,60 @@ public class ARRAYS
 		}
 	}
 	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Selection Sort,
+	 * On top of that allows to sort other things along with it.
+	 * @param array the array that needs to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 * @return input array
+	 */
+	public static GENERIC_KEY_BRACES KEY_TYPE[] indirectSelectionSort(KEY_TYPE[] array, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectSelectionSort(array, 0, array.length, comp, swapper);
+		return array;
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Selection Sort,
+	 * On top of that allows to sort other things along with it.
+	 * @param array the array that needs to be sorted
+	 * @param length the maxmium size of the array to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectSelectionSort(KEY_TYPE[] array, int length, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectSelectionSort(array, 0, length, comp, swapper);
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Selection Sort,
+	 * On top of that allows to sort other things along with it.
+	 * @param array the array that needs to be sorted
+	 * @param from where the array should be sorted from
+	 * @param to where the array should be sorted to
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectSelectionSort(KEY_TYPE[] array, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		for (int i = from; i < to; i++) {
+			KEY_TYPE min = array[i];
+			int minId = i;
+			for(int j = i+1; j < to; j++) {
+				if(comp.compare(array[j], min) < 0) {
+					min = array[j];
+					minId = j;
+				}
+			}
+			swapper.swap(i, minId);
+			KEY_TYPE temp = array[i];
+			array[i] = min;
+			array[minId] = temp;
+		}
+	}
+	
 	/**
 	 * Sorts an array according to the natural ascending order using Selection Sort, 
 	 * @param array the array that needs to be sorted
@@ -760,6 +927,72 @@ public class ARRAYS
 		}
 	}
 	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Merge Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation was copied from <a href="https://github.com/vigna/fastutil">FastUtil</a> with a couple custom optimizations
+	 * @param array the array that needs to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 * @return input array
+	 */
+	public static GENERIC_KEY_BRACES KEY_TYPE[] indirectMergeSort(KEY_TYPE[] array, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectMergeSort(array, null, 0, array.length, comp, swapper);
+		return array;
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Merge Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation was copied from <a href="https://github.com/vigna/fastutil">FastUtil</a> with a couple custom optimizations
+	 * @param array the array that needs to be sorted
+	 * @param length the maxmium size of the array to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectMergeSort(KEY_TYPE[] array, int length, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectMergeSort(array, null, 0, length, comp, swapper);
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Merge Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation was copied from <a href="https://github.com/vigna/fastutil">FastUtil</a> with a couple custom optimizations
+	 * @param array the array that needs to be sorted
+	 * @param supp the auxillary array that is used to simplify the sorting
+	 * @param from where the array should be sorted from
+	 * @param to where the array should be sorted to
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectMergeSort(KEY_TYPE[] array, KEY_TYPE[] supp, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		if(to - from < BASE_THRESHOLD) {
+			indirectInsertionSort(array, from, to, comp, swapper);
+			return;
+		}
+		if(supp == null) supp = Arrays.copyOf(array, to);
+		int mid = (from + to) >>> 1;
+		indirectMergeSort(supp, array, from, mid, comp, swapper);
+		indirectMergeSort(supp, array, mid, to, comp, swapper);
+		if(comp.compare(supp[mid - 1], supp[mid]) <= 0)
+		{
+			System.arraycopy(supp, from, array, from, to - from);
+			return;
+		}
+		for(int p = from, q = mid;from < to;from++) {
+			if(q >= to || p < mid && comp.compare(supp[p], supp[q]) < 0) {
+				swapper.swap(from, p);
+				array[from] = supp[p++];
+				continue;
+			}
+			swapper.swap(from, q);
+			array[from] = supp[q++];
+		}
+	}
+	
 	/**
 	 * Sorts an array according to the natural ascending order using Merge Sort, 
 	 * This implementation was copied from <a href="https://github.com/vigna/fastutil">FastUtil</a> with a couple custom optimizations
@@ -856,6 +1089,56 @@ public class ARRAYS
 		mergeSort(array, supp, from, to, comp);
 	}
 	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using a Parallel Merge Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation was copied from <a href="https://github.com/vigna/fastutil">FastUtil</a> with a couple custom optimizations
+	 * @param array the array that needs to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @note This parallelization is invoked through {@link SanityChecks#invokeTask} which the threadpool can be changed as needed
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectParallelMergeSort(KEY_TYPE[] array, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectParallelMergeSort(array, null, 0, array.length, comp, swapper);
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Parallel Merge Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation was copied from <a href="https://github.com/vigna/fastutil">FastUtil</a> with a couple custom optimizations
+	 * @param array the array that needs to be sorted
+	 * @param length the maxmium size of the array to be sorted
+	 * @param swapper the callback which elements were swapped
+	 * @param comp the Comparator that decides the sorting order
+	 * @note This parallelization is invoked through {@link SanityChecks#invokeTask} which the threadpool can be changed as needed
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectParallelMergeSort(KEY_TYPE[] array, int length, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectParallelMergeSort(array, null, 0, length, comp, swapper);
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Parallel Merge Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation was copied from <a href="https://github.com/vigna/fastutil">FastUtil</a> with a couple custom optimizations
+	 * @param array the array that needs to be sorted
+	 * @param supp the auxillary array that is used to simplify the sorting
+	 * @param from where the array should be sorted from
+	 * @param to where the array should be sorted to
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @note This parallelization is invoked through {@link SanityChecks#invokeTask} which the threadpool can be changed as needed
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectParallelMergeSort(KEY_TYPE[] array, KEY_TYPE[] supp, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		if(SanityChecks.canParallelTask() && to - from >= PARALLEL_THRESHOLD) {
+			SanityChecks.invokeTask(new MergeSortActionCompSwapBRACES(array, supp, from, to, comp, swapper));
+			return;
+		}
+		indirectMergeSort(array, supp, from, to, comp, swapper);
+	}
+	
 	/**
 	 * Sorts an array according to the natural ascending order using Parallel Merge Sort, 
 	 * This implementation was copied from <a href="https://github.com/vigna/fastutil">FastUtil</a> with a couple custom optimizations
@@ -1209,6 +1492,73 @@ public class ARRAYS
 		if((length = d - c) > 1) quickSort(array, to - length, to, comp);
 	}
 	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Quick Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation is a custom of <a href="https://github.com/vigna/fastutil">FastUtil</a> quicksort but with a different code structure,
+	 * and that sorting Algorithm is based on the tuned quicksort adapted from Jon L. Bentley and M. DouglasMcIlroy, "Engineering a Sort Function", Software: Practice and Experience, 23(11), pages1249−1265, 1993. 
+	 * @param array the array that needs to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 * @return input array
+	 */
+	public static GENERIC_KEY_BRACES KEY_TYPE[] indirectQuickSort(KEY_TYPE[] array, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectQuickSort(array, 0, array.length, comp, swapper);
+		return array;
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Quick Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation is a custom of <a href="https://github.com/vigna/fastutil">FastUtil</a> quicksort but with a different code structure,
+	 * and that sorting Algorithm is based on the tuned quicksort adapted from Jon L. Bentley and M. DouglasMcIlroy, "Engineering a Sort Function", Software: Practice and Experience, 23(11), pages1249−1265, 1993. 
+	 * @param array the array that needs to be sorted
+	 * @param length the maxmium size of the array to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectQuickSort(KEY_TYPE[] array, int length, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectQuickSort(array, 0, length, comp, swapper);
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Quick Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation is a custom of <a href="https://github.com/vigna/fastutil">FastUtil</a> quicksort but with a different code structure,
+	 * and that sorting Algorithm is based on the tuned quicksort adapted from Jon L. Bentley and M. DouglasMcIlroy, "Engineering a Sort Function", Software: Practice and Experience, 23(11), pages1249−1265, 1993. 
+	 * @param array the array that needs to be sorted
+	 * @param from where the array should be sorted from
+	 * @param to where the array should be sorted to
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 */
+	public static GENERIC_KEY_BRACES void indirectQuickSort(KEY_TYPE[] array, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		int length = to - from;
+		if(length <= 0) return;
+		if(length < BASE_THRESHOLD) {
+			indirectSelectionSort(array, from, to, comp, swapper);
+			return;			
+		}
+		KEY_TYPE pivot = array[length > 128 ? subMedium(array, from, from + (length / 2), to - 1, length / 8, comp) : medium(array, from, from + (length / 2), to - 1, comp)];
+		int a = from, b = a, c = to - 1, d = c;
+		for(int compare;;swap(array, b++, c--, swapper)) {
+			for(;b<=c && (compare = comp.compare(array[b], pivot)) <= 0;b++) {
+				if(compare == 0) swap(array, a++, b, swapper);
+			}
+			for(;c>=b && (compare = comp.compare(array[c], pivot)) >= 0;c--) {
+				if(compare == 0) swap(array, c, d--, swapper);
+			}
+			if(b>c) break;
+		}
+		swap(array, from, b, Math.min(a - from, b - a), swapper); 
+		swap(array, b, to, Math.min(d - c, to - d - 1), swapper);
+		if((length = b - a) > 1) indirectQuickSort(array, from, from + length, comp, swapper);
+		if((length = d - c) > 1) indirectQuickSort(array, to - length, to, comp, swapper);
+	}
+	
 	/**
 	 * Sorts an array according to the natural ascending order using Quick Sort, 
 	 * This implementation is a custom of <a href="https://github.com/vigna/fastutil">FastUtil</a> quicksort but with a different code structure,
@@ -1313,6 +1663,58 @@ public class ARRAYS
 		quickSort(array, from, to, comp);
 	}
 	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Parallel Quick Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation is a custom of <a href="https://github.com/vigna/fastutil">FastUtil</a> quicksort but with a different code structure,
+	 * and that sorting Algorithm is based on the tuned quicksort adapted from Jon L. Bentley and M. DouglasMcIlroy, "Engineering a Sort Function", Software: Practice and Experience, 23(11), pages1249−1265, 1993. 
+	 * @param array the array that needs to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 * @note This parallelization is invoked through {@link SanityChecks#invokeTask} which the threadpool can be changed as needed
+	 */
+	public static GENERIC_KEY_BRACES void indirectParallelQuickSort(KEY_TYPE[] array, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectParallelQuickSort(array, 0, array.length, comp, swapper);
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Parallel Quick Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation is a custom of <a href="https://github.com/vigna/fastutil">FastUtil</a> quicksort but with a different code structure,
+	 * and that sorting Algorithm is based on the tuned quicksort adapted from Jon L. Bentley and M. DouglasMcIlroy, "Engineering a Sort Function", Software: Practice and Experience, 23(11), pages1249−1265, 1993. 
+	 * @param array the array that needs to be sorted
+	 * @param length the maxmium size of the array to be sorted
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 * @note This parallelization is invoked through {@link SanityChecks#invokeTask} which the threadpool can be changed as needed
+	 */
+	public static GENERIC_KEY_BRACES void indirectParallelQuickSort(KEY_TYPE[] array, int length, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		indirectParallelQuickSort(array, 0, length, comp, swapper);
+	}
+	
+	/**
+	 * Sorts the specified range of elements according to the order induced by the specified comparator using Parallel Quick Sort,
+	 * On top of that allows to sort other things along with it.
+	 * This implementation is a custom of <a href="https://github.com/vigna/fastutil">FastUtil</a> quicksort but with a different code structure,
+	 * and that sorting Algorithm is based on the tuned quicksort adapted from Jon L. Bentley and M. DouglasMcIlroy, "Engineering a Sort Function", Software: Practice and Experience, 23(11), pages1249−1265, 1993. 
+	 * @param array the array that needs to be sorted
+	 * @param from where the array should be sorted from
+	 * @param to where the array should be sorted to
+	 * @param comp the Comparator that decides the sorting order
+	 * @param swapper the callback which elements were swapped
+	 * @ArrayType(T)
+	 * @note This parallelization is invoked through {@link SanityChecks#invokeTask} which the threadpool can be changed as needed
+	 */
+	public static GENERIC_KEY_BRACES void indirectParallelQuickSort(KEY_TYPE[] array, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+		if(SanityChecks.canParallelTask() && to - from >= PARALLEL_THRESHOLD) {
+			SanityChecks.invokeTask(new QuickSortActionCompSwapBRACES(array, from, to, comp, swapper));
+			return;
+		}
+		indirectQuickSort(array, from, to, comp, swapper);
+	}
+	
 	/**
 	 * Sorts an array according to the natural ascending order using Parallel Quick Sort, 
 	 * This implementation is a custom of <a href="https://github.com/vigna/fastutil">FastUtil</a> quicksort but with a different code structure,
@@ -1367,6 +1769,18 @@ public class ARRAYS
 		for(int i = 0;i<length;i++,swap(a, from++, to++));
 	}
 	
+	static GENERIC_KEY_BRACES void swap(KEY_TYPE[] a, int from, int to, Swapper swapper) {
+		swapper.swap(from, to);
+		KEY_TYPE t = a[from];
+		a[from] = a[to];
+		a[to] = t;
+	}
+	
+	static GENERIC_KEY_BRACES void swap(KEY_TYPE[] a, int from, int to, int length, Swapper swapper) {
+		to -= length;
+		for(int i = 0;i<length;i++,swap(a, from++, to++, swapper));
+	}
+	
 	static GENERIC_KEY_BRACES int subMedium(KEY_TYPE[] data, int a, int b, int c, int length, COMPARATOR KEY_GENERIC_TYPE comp) {
 		return medium(data, medium(data, a, a + length, a + (length * 2), comp), medium(data, b - length, b, b + length, comp), medium(data, c - (length * 2), c - length, c, comp), comp);
 	}
@@ -1389,16 +1803,14 @@ public class ARRAYS
 		int from;
 		int to;
 		
-		QuickSortAction(KEY_TYPE[] array, int from, int to)
-		{
+		QuickSortAction(KEY_TYPE[] array, int from, int to) {
 			this.array = array;
 			this.from = from;
 			this.to = to;
 		}
 		
 		@Override
-		protected void compute()
-		{
+		protected void compute() {
 			int length = to - from;
 			if(length <= 0) return;
 			if(length < BASE_THRESHOLD) {
@@ -1431,8 +1843,7 @@ public class ARRAYS
 		int to;
 		COMPARATOR KEY_GENERIC_TYPE comp;
 		
-		QuickSortActionComp(KEY_TYPE[] array, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp)
-		{
+		QuickSortActionComp(KEY_TYPE[] array, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp) {
 			this.array = array;
 			this.from = from;
 			this.to = to;
@@ -1440,8 +1851,7 @@ public class ARRAYS
 		}
 		
 		@Override
-		protected void compute()
-		{
+		protected void compute() {
 			int length = to - from;
 			if(length <= 0) return;
 			if(length < BASE_THRESHOLD) {
@@ -1467,6 +1877,49 @@ public class ARRAYS
 		}
 	}
 	
+	static class QuickSortActionCompSwap KEY_GENERIC_TYPE extends RecursiveAction {
+		private static final long serialVersionUID = 0L;
+		KEY_TYPE[] array;
+		int from;
+		int to;
+		COMPARATOR KEY_GENERIC_TYPE comp;
+		Swapper swapper;
+		
+		QuickSortActionCompSwap(KEY_TYPE[] array, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+			this.array = array;
+			this.from = from;
+			this.to = to;
+			this.comp = comp;
+			this.swapper = swapper;
+		}
+		
+		@Override
+		protected void compute() {
+			int length = to - from;
+			if(length <= 0) return;
+			if(length < BASE_THRESHOLD) {
+				indirectSelectionSort(array, from, to, comp, swapper);
+				return;			
+			}
+			KEY_TYPE pivot = array[length > 128 ? subMedium(array, from, from + (length / 2), to - 1, length / 8, comp) : medium(array, from, from + (length / 2), to - 1, comp)];
+			int a = from, b = a, c = to - 1, d = c;
+			for(int compare;;swap(array, b++, c--, swapper)) {
+				for(;b<=c && (compare = comp.compare(array[b], pivot)) <= 0;b++) {
+					if(compare == 0) swap(array, a++, b, swapper);
+				}
+				for(;c>=b && (compare = comp.compare(array[c], pivot)) >= 0;c--) {
+					if(compare == 0) swap(array, c, d--, swapper);
+				}
+				if(b>c) break;
+			}
+			swap(array, from, b, Math.min(a - from, b - a), swapper); 
+			swap(array, b, to, Math.min(d - c, to - d - 1), swapper);
+			if(b - a > 1 && d - c > 1) invokeAll(new QuickSortActionCompSwapBRACES(array, from, from + (b - a), comp, swapper), new QuickSortActionCompSwapBRACES(array, to - (d - c), to, comp, swapper));
+			else if(b - a > 1) new QuickSortActionCompSwapBRACES(array, from, from + (b - a), comp, swapper).invoke();
+			else if(d - c > 1) new QuickSortActionCompSwapBRACES(array, to - (d - c), to, comp, swapper).invoke();
+		}
+	}
+	
 	static class MergeSortAction KEY_GENERIC_TYPE extends RecursiveAction {
 		private static final long serialVersionUID = 0L;
 		KEY_TYPE[] array;
@@ -1474,8 +1927,7 @@ public class ARRAYS
 		int from;
 		int to;
 		
-		MergeSortAction(KEY_TYPE[] array, KEY_TYPE[] supp, int from, int to)
-		{
+		MergeSortAction(KEY_TYPE[] array, KEY_TYPE[] supp, int from, int to) {
 			this.array = array;
 			this.supp = supp;
 			this.from = from;
@@ -1483,8 +1935,7 @@ public class ARRAYS
 		}
 		
 		@Override
-		protected void compute()
-		{
+		protected void compute() {
 			if(to - from < BASE_THRESHOLD) {
 				insertionSort(array, from, to);
 				return;
@@ -1512,8 +1963,7 @@ public class ARRAYS
 		int to;
 		COMPARATOR KEY_GENERIC_TYPE comp;
 		
-		MergeSortActionComp(KEY_TYPE[] array, KEY_TYPE[] supp, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp)
-		{
+		MergeSortActionComp(KEY_TYPE[] array, KEY_TYPE[] supp, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp) {
 			this.array = array;
 			this.supp = supp;
 			this.from = from;
@@ -1522,8 +1972,7 @@ public class ARRAYS
 		}
 		
 		@Override
-		protected void compute()
-		{
+		protected void compute() {
 			if(to - from < BASE_THRESHOLD) {
 				insertionSort(array, from, to, comp);
 				return;
@@ -1543,22 +1992,64 @@ public class ARRAYS
 		}
 	}
 	
+	static class MergeSortActionCompSwap KEY_GENERIC_TYPE extends RecursiveAction {
+		private static final long serialVersionUID = 0L;
+		KEY_TYPE[] array;
+		KEY_TYPE[] supp;
+		int from;
+		int to;
+		COMPARATOR KEY_GENERIC_TYPE comp;
+		Swapper swapper;
+		
+		MergeSortActionCompSwap(KEY_TYPE[] array, KEY_TYPE[] supp, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp, Swapper swapper) {
+			this.array = array;
+			this.supp = supp;
+			this.from = from;
+			this.to = to;
+			this.comp = comp;
+			this.swapper = swapper;
+		}
+		
+		@Override
+		protected void compute() {
+			if(to - from < BASE_THRESHOLD) {
+				indirectInsertionSort(array, from, to, comp, swapper);
+				return;
+			}
+			if(supp == null) supp = Arrays.copyOf(array, to);
+			int mid = (from + to) >>> 1;
+			invokeAll(new MergeSortActionCompSwapBRACES(supp, array, from, mid, comp, swapper), new MergeSortActionCompSwapBRACES(supp, array, mid, to, comp, swapper));
+			if(comp.compare(supp[mid - 1], supp[mid]) <= 0)
+			{
+				System.arraycopy(supp, from, array, from, to - from);
+				return;
+			}
+			for(int p = from, q = mid;from < to;from++) {
+				if(q >= to || p < mid && comp.compare(supp[p], supp[q]) < 0) {
+					swapper.swap(from, p);
+					array[from] = supp[p++];
+					continue;
+				}
+				swapper.swap(from, q);
+				array[from] = supp[q++];
+			}
+		}
+	}
+	
 	static class MemFreeMergeSortAction KEY_GENERIC_TYPE extends RecursiveAction {
 		private static final long serialVersionUID = 0L;
 		KEY_TYPE[] array;
 		int from;
 		int to;
 		
-		MemFreeMergeSortAction(KEY_TYPE[] array, int from, int to)
-		{
+		MemFreeMergeSortAction(KEY_TYPE[] array, int from, int to) {
 			this.array = array;
 			this.from = from;
 			this.to = to;
 		}
 		
 		@Override
-		protected void compute()
-		{
+		protected void compute() {
 			if(to - from < BASE_THRESHOLD) {
 				insertionSort(array, from, to);
 				return;
@@ -1604,8 +2095,7 @@ public class ARRAYS
 		int to;
 		COMPARATOR KEY_GENERIC_TYPE comp;
 		
-		MemFreeMergeSortActionComp(KEY_TYPE[] array, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp)
-		{
+		MemFreeMergeSortActionComp(KEY_TYPE[] array, int from, int to, COMPARATOR KEY_GENERIC_TYPE comp) {
 			this.array = array;
 			this.from = from;
 			this.to = to;
@@ -1613,8 +2103,7 @@ public class ARRAYS
 		}
 		
 		@Override
-		protected void compute()
-		{
+		protected void compute() {
 			if(to - from < BASE_THRESHOLD) {
 				insertionSort(array, from, to, comp);
 				return;
@@ -7,6 +7,11 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 import java.util.concurrent.locks.LockSupport;
 import java.util.function.Consumer;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#else
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT

 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -299,9 +304,8 @@ public class ASYNC_BUILDER KEY_GENERIC_TYPE
 	 * @param operator that reduces the elements.
 	 * @return self with the reduce action applied
 	 */
-	public ASYNC_BUILDER KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
-		task = new SimpleReduceTaskBRACES(iterable.iterator(), operator);
-		return this;
+	public ObjectAsyncBuilder<OPTIONAL KEY_GENERIC_TYPE> reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		return new ObjectAsyncBuilder<>(new SimpleReduceTaskBRACES(iterable.iterator(), operator));
 	}
 	
 #if TYPE_OBJECT
@@ -435,9 +439,8 @@ public class ASYNC_BUILDER KEY_GENERIC_TYPE
 	 * @param filter that decides the desired elements
 	 * @return self with the findFirst function applied
 	 */
-	public ASYNC_BUILDER KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
-		task = new FindFirstTaskBRACES(iterable.iterator(), filter);
-		return this;
+	public ObjectAsyncBuilder<OPTIONAL KEY_GENERIC_TYPE> findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		return new ObjectAsyncBuilder<>(new FindFirstTaskBRACES(iterable.iterator(), filter));
 	}
 	
 #if INT_ASYNC_MODULE
@@ -590,7 +593,7 @@ public class ASYNC_BUILDER KEY_GENERIC_TYPE
 	}
 	
 #endif
-	private static class SimpleReduceTask KEY_GENERIC_TYPE extends BASE_TASK KEY_GENERIC_TYPE
+	private static class SimpleReduceTask KEY_GENERIC_TYPE extends BaseObjectTask<OPTIONAL KEY_GENERIC_TYPE>
 	{
 		ITERATOR KEY_GENERIC_TYPE iter;
 		UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator;
@@ -600,6 +603,7 @@ public class ASYNC_BUILDER KEY_GENERIC_TYPE
 		public SimpleReduceTask(ITERATOR KEY_GENERIC_TYPE iter, UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			this.iter = iter;
 			this.operator = operator;
+			this.setResult(OPTIONAL.empty());
 		}
 		
 		@Override
@@ -614,7 +618,7 @@ public class ASYNC_BUILDER KEY_GENERIC_TYPE
 				}
 			}
 			if(!iter.hasNext()) {
-				setResult(value);
+				setResult(OPTIONAL.GET_OPTIONAL(value));
 				return true;
 			}
 			return false;
@@ -689,7 +693,7 @@ public class ASYNC_BUILDER KEY_GENERIC_TYPE
 	}
 	
 #endif
-	private static class FindFirstTask KEY_GENERIC_TYPE extends BASE_TASK KEY_GENERIC_TYPE
+	private static class FindFirstTask KEY_GENERIC_TYPE extends BaseObjectTask<OPTIONAL KEY_GENERIC_TYPE>
 	{
 		ITERATOR KEY_GENERIC_TYPE iter;
 		PREDICATE KEY_GENERIC_TYPE filter;
@@ -697,6 +701,7 @@ public class ASYNC_BUILDER KEY_GENERIC_TYPE
 		public FindFirstTask(ITERATOR KEY_GENERIC_TYPE iter, PREDICATE KEY_GENERIC_TYPE filter) {
 			this.iter = iter;
 			this.filter = filter;
+			this.setResult(OPTIONAL.empty());
 		}

 		@Override
@@ -704,7 +709,7 @@ public class ASYNC_BUILDER KEY_GENERIC_TYPE
 			while(shouldRun() && iter.hasNext()) {
 				KEY_TYPE entry = iter.NEXT();
 				if(filter.test(iter.NEXT())) {
-					setResult(entry);
+					setResult(OPTIONAL.GET_OPTIONAL(entry));
 					return true;
 				}
 			}
@@ -8,6 +8,9 @@ import java.util.ConcurrentModificationException;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if TYPE_OBJECT
 import java.util.Comparator;
 import java.util.function.BiFunction;
@@ -23,10 +26,16 @@ import java.util.function.Consumer;

 import speiger.src.collections.PACKAGE.collections.ABSTRACT_COLLECTION;
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
+#if ORDERED_MAP_FEATURE
+import speiger.src.collections.PACKAGE.collections.ORDERED_COLLECTION;
+#endif
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.objects.utils.ObjectArrays;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -76,6 +85,37 @@ public class COLLECTIONS
 		return c instanceof UnmodifiableCollection ? c : new UnmodifiableCollectionBRACES(c);
 	}
 	
+	/**
+	 * Returns a Immutable Ordered Collection instance based on the instance given.
+	 * @param c that should be made immutable/unmodifiable
+	 * @Type(T)
+	 * @return a unmodifiable Ordered collection wrapper. If the Collection already a unmodifiable wrapper then it just returns itself.
+	 */
+	public static GENERIC_KEY_BRACES ORDERED_COLLECTION KEY_GENERIC_TYPE unmodifiable(ORDERED_COLLECTION KEY_GENERIC_TYPE c) {
+		return c instanceof UnmodifiableOrderedCollection ? c : new UnmodifiableOrderedCollectionBRACES(c);
+	}
+	
+	/**
+	 * Returns a synchronized ordered Collection instance based on the instance given.
+	 * @param c that should be synchronized
+	 * @Type(T)
+	 * @return a synchronized ordered collection wrapper. If the Collection already a synchronized wrapper then it just returns itself.
+	 */
+	public static GENERIC_KEY_BRACES ORDERED_COLLECTION KEY_GENERIC_TYPE synchronize(ORDERED_COLLECTION KEY_GENERIC_TYPE c) {
+		return c instanceof SynchronizedOrderedCollection ? c : new SynchronizedOrderedCollectionBRACES(c);
+	}
+	
+	/**
+	 * Returns a synchronized ordered Collection instance based on the instance given.
+	 * @param c that should be synchronized
+	 * @param mutex is the controller of the synchronization block.
+	 * @Type(T)
+	 * @return a synchronized ordered collection wrapper. If the Collection already a synchronized wrapper then it just returns itself.
+	 */
+	public static GENERIC_KEY_BRACES ORDERED_COLLECTION KEY_GENERIC_TYPE synchronize(ORDERED_COLLECTION KEY_GENERIC_TYPE c, Object mutex) {
+		return c instanceof SynchronizedOrderedCollection ? c : new SynchronizedOrderedCollectionBRACES(c, mutex);
+	}
+	
 	/**
 	 * Returns a synchronized Collection instance based on the instance given.
 	 * @param c that should be synchronized
@@ -107,7 +147,10 @@ public class COLLECTIONS
 		return new SingletonCollectionBRACES(element);
 	}
 	
-	protected static GENERIC_KEY_BRACES CollectionWrapper KEY_GENERIC_TYPE wrapper() {
+	/**
+	 * Internal Use mainly. Its a collection wrapper with 0 dependencies for those actions where a collector is needed.
+	 */
+	public static GENERIC_KEY_BRACES CollectionWrapper KEY_GENERIC_TYPE wrapper() {
 		return new CollectionWrapperBRACES();
 	}
 	
@@ -668,6 +711,38 @@ public class COLLECTIONS
 		@Override
 		public SingletonCollection KEY_GENERIC_TYPE copy() { return new SingletonCollectionBRACES(element); }
 	}
+	/**
+	 * Synchronized Ordered Collection Wrapper for the synchronizedCollection function
+	 * @Type(T)
+	 */
+	public static class SynchronizedOrderedCollection KEY_GENERIC_TYPE extends SynchronizedCollection KEY_GENERIC_TYPE implements ORDERED_COLLECTION KEY_GENERIC_TYPE {
+		ORDERED_COLLECTION KEY_GENERIC_TYPE c;
+		
+		SynchronizedOrderedCollection(ORDERED_COLLECTION KEY_GENERIC_TYPE c, Object mutex) {
+			super(c, mutex);
+			this.c = c;
+		}
+		
+		SynchronizedOrderedCollection(ORDERED_COLLECTION KEY_GENERIC_TYPE c) {
+			super(c);
+			this.c = c;
+		}
+		
+		@Override
+		public ORDERED_COLLECTION KEY_GENERIC_TYPE reversed() { return COLLECTIONS.synchronize(c.reversed(), mutex); }
+		@Override
+		public void addFirst(KEY_TYPE e) { synchronized(mutex) { this.c.addFirst(e); } }
+		@Override
+		public void addLast(KEY_TYPE e) { synchronized(mutex) { this.c.addLast(e); } }
+		@Override
+		public KEY_TYPE GET_FIRST_KEY() { synchronized(mutex) { return this.c.GET_FIRST_KEY(); } }
+		@Override
+		public KEY_TYPE REMOVE_FIRST_KEY() { synchronized(mutex) { return this.c.REMOVE_FIRST_KEY(); } }
+		@Override
+		public KEY_TYPE GET_LAST_KEY() { synchronized(mutex) { return this.c.GET_LAST_KEY(); } }
+		@Override
+		public KEY_TYPE REMOVE_LAST_KEY() { synchronized(mutex) { return this.c.REMOVE_LAST_KEY(); } }
+	}	
 	
 	/**
 	 * Synchronized Collection Wrapper for the synchronizedCollection function
@@ -803,13 +878,41 @@ public class COLLECTIONS
 		public KEY_TYPE reduce(KEY_TYPE identity, UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { synchronized(mutex) { return c.reduce(identity, operator); } }
 #endif
 		@Override
-		public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { synchronized(mutex) { return c.reduce(operator); } }
+		public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { synchronized(mutex) { return c.reduce(operator); } }
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return c.findFirst(filter); } }
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return c.findFirst(filter); } }
 		@Override
 		public int count(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return c.count(filter); } }
 	}
 	
+	/**
+	 * Unmodifyable Ordered Collection Wrapper for the unmodifyableCollection method
+	 * @Type(T)
+	 */
+	public static class UnmodifiableOrderedCollection KEY_GENERIC_TYPE extends UnmodifiableCollection KEY_GENERIC_TYPE implements ORDERED_COLLECTION KEY_GENERIC_TYPE {
+		ORDERED_COLLECTION KEY_GENERIC_TYPE c;
+		
+		UnmodifiableOrderedCollection(ORDERED_COLLECTION KEY_GENERIC_TYPE c) {
+			super(c);
+			this.c = c;
+		}
+		
+		@Override
+		public ORDERED_COLLECTION KEY_GENERIC_TYPE reversed() { return COLLECTIONS.unmodifiable(c.reversed()); }
+		@Override
+		public void addFirst(KEY_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(KEY_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public KEY_TYPE GET_FIRST_KEY() { return c.GET_FIRST_KEY(); }
+		@Override
+		public KEY_TYPE REMOVE_FIRST_KEY() { throw new UnsupportedOperationException(); }
+		@Override
+		public KEY_TYPE GET_LAST_KEY() { return c.GET_LAST_KEY(); }
+		@Override
+		public KEY_TYPE REMOVE_LAST_KEY() { throw new UnsupportedOperationException(); }
+	}
+	
 	/**
 	 * Unmodifyable Collection Wrapper for the unmodifyableCollection method
 	 * @Type(T)
@@ -927,9 +1030,9 @@ public class COLLECTIONS
 		public KEY_TYPE reduce(KEY_TYPE identity, UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { return c.reduce(identity, operator); }
 #endif
 		@Override
-		public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { return c.reduce(operator); }
+		public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { return c.reduce(operator); }
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { return c.findFirst(filter); }
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { return c.findFirst(filter); }
 		@Override
 		public int count(PREDICATE KEY_GENERIC_TYPE filter) { return c.count(filter); }
 	}
@@ -342,6 +342,8 @@ public class ITERABLES
 #argument MAPPER Predicate ToByteFunction ToShortFunction ToIntFunction ToLongFunction ToFloatFunction ToDoubleFunction
 #argument APPLY test applyAsByte applyAsShort applyAsInt applyAsLong applyAsFloat applyAsDouble
 #argument DATA_TYPE Boolean Byte Short Int Long Float Double
+#argument FILTER_TYPE BOOLEAN_COLLECTION_MODULE BYTE_COLLECTION_MODULE SHORT_COLLECTION_MODULE INT_COLLECTION_MODULE LONG_COLLECTION_MODULE FLOAT_COLLECTION_MODULE DOUBLE_COLLECTION_MODULE
+#if FILTER_TYPE
 	private static class MAPPED_TYPEIterable<E> implements OUTPUT_ITERABLE, ISizeProvider
 	{
 		ITERABLE KEY_SPECIAL_GENERIC_TYPE<E> iterable;
@@ -369,6 +371,7 @@ public class ITERABLES
 		}
 	}
 	
+#endif
 #enditerate
 #endif
 	private static class MappedIterable KSS_GENERIC_TYPE<E, T> implements ObjectIterable<T>, ISizeProvider
@@ -25,7 +25,7 @@ import speiger.src.collections.booleans.collections.BooleanIterator;
 #argument PACKAGE bytes shorts ints longs floats doubles
 #argument MAPPER ToByteFunction ToShortFunction ToIntFunction ToLongFunction ToFloatFunction ToDoubleFunction
 #argument FILTER_TYPE BYTE_COLLECTION_MODULE SHORT_COLLECTION_MODULE INT_COLLECTION_MODULE LONG_COLLECTION_MODULE FLOAT_COLLECTION_MODULE DOUBLE_COLLECTION_MODULE
-#if BOOLEAN_COLLECTION_MODULE
+#if FILTER_TYPE
 import speiger.src.collections.objects.functions.function.MAPPER;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
 #endif
@@ -65,7 +65,7 @@ public class ITERATORS
 	 * @Type(T)
 	 * @return an empty iterator
 	 */
-	public static GENERIC_KEY_BRACES EmptyIterator KEY_GENERIC_TYPE empty() {
+	public static GENERIC_KEY_BRACES LIST_ITERATOR KEY_GENERIC_TYPE empty() {
 #if TYPE_OBJECT
 		return (EmptyIterator<KEY_TYPE>)EMPTY;
 #else
@@ -400,7 +400,7 @@ public class ITERATORS
 	 * @ArrayType(T)
 	 * @return a Iterator that is wrapping a array.
 	 */
-	public static GENERIC_KEY_BRACES ArrayIterator KEY_GENERIC_TYPE wrap(KEY_TYPE... a) {
+	public static GENERIC_KEY_BRACES ITERATOR KEY_GENERIC_TYPE wrap(KEY_TYPE... a) {
 		return wrap(a, 0, a.length);
 	}
 	
@@ -412,7 +412,7 @@ public class ITERATORS
 	 * @ArrayType(T)
 	 * @return a Iterator that is wrapping a array.
 	 */
-	public static GENERIC_KEY_BRACES ArrayIterator KEY_GENERIC_TYPE wrap(KEY_TYPE[] a, int start, int end) {
+	public static GENERIC_KEY_BRACES ITERATOR KEY_GENERIC_TYPE wrap(KEY_TYPE[] a, int start, int end) {
 		return new ArrayIteratorBRACES(a, start, end);
 	}
 	
@@ -925,6 +925,8 @@ public class ITERATORS
 #argument MAPPER Predicate ToByteFunction ToShortFunction ToIntFunction ToLongFunction ToFloatFunction ToDoubleFunction
 #argument APPLY test applyAsByte applyAsShort applyAsInt applyAsLong applyAsFloat applyAsDouble
 #argument DATA_TYPE boolean byte short int long float double
+#argument FILTER_TYPE BOOLEAN_COLLECTION_MODULE BYTE_COLLECTION_MODULE SHORT_COLLECTION_MODULE INT_COLLECTION_MODULE LONG_COLLECTION_MODULE FLOAT_COLLECTION_MODULE DOUBLE_COLLECTION_MODULE
+#if FILTER_TYPE
 	private static class MAPPED_TYPEIterator<E> implements OUTPUT_ITERATOR
 	{
 		ITERATOR<E> iterator;
@@ -951,6 +953,7 @@ public class ITERATORS
 		}
 	}
 	
+#endif
 #enditerate
 #endif
 	private static class FlatMappedIterator KSS_GENERIC_TYPE<E, T,[SPACE]V extends Iterable<T>> implements ObjectIterator<T>
@@ -45,7 +45,7 @@ public class LISTS
 	 * @Type(T)
 	 * @return an empty list
 	 */
-	public static GENERIC_KEY_BRACES EmptyList KEY_GENERIC_TYPE empty() {
+	public static GENERIC_KEY_BRACES LIST KEY_GENERIC_TYPE empty() {
 #if TYPE_OBJECT
 		return (EmptyList<KEY_TYPE>)EMPTY;
 #else
@@ -4,16 +4,22 @@ package speiger.src.collections.PACKAGE.utils;
 import java.util.Collection;
 import java.util.Comparator;
 import java.util.function.Consumer;
+import java.util.function.BiFunction;
 #endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
-
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if DEQUEUE_FEATURE
 import speiger.src.collections.PACKAGE.queues.PRIORITY_DEQUEUE;
 #endif
@@ -24,6 +30,7 @@ import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #if !JDK_FUNCTION
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;

 /**
@@ -140,7 +147,15 @@ public class PRIORITY_QUEUES
 		@Override
 		public boolean matchesAll(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return queue.matchesAll(filter); } }
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return queue.findFirst(filter); } }
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return queue.findFirst(filter); } }
+		#if TYPE_OBJECT
+		public <KEY_SPECIAL_TYPE> KEY_SPECIAL_TYPE reduce(KEY_SPECIAL_TYPE identity, BiFunction<KEY_SPECIAL_TYPE, KEY_TYPE, KEY_SPECIAL_TYPE> operator) { synchronized(mutex) { return queue.reduce(identity, operator); } }
+#else
+		@Override
+		public KEY_TYPE reduce(KEY_TYPE identity, UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { synchronized(mutex) { return queue.reduce(identity, operator); } }
+#endif
+		@Override
+		public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { synchronized(mutex) { return queue.reduce(operator); } }
 		@Override
 		public int count(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return queue.count(filter); } }
 	}
@@ -360,6 +360,10 @@ public class SETS
 			s = c;
 		}
 		
+		@Override
+		public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -371,17 +375,19 @@ public class SETS
 		@Override
 		public BI_ITERATOR KEY_GENERIC_TYPE iterator() { return ITERATORS.unmodifiable(s.iterator()); }
 		@Override
+		public BI_ITERATOR KEY_GENERIC_TYPE reverseIterator() { return ITERATORS.unmodifiable(s.reverseIterator()); }
+		@Override
 		public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) { return ITERATORS.unmodifiable(s.iterator(fromElement)); }
 		@Override
 		public ORDERED_SET KEY_GENERIC_TYPE copy() { return s.copy(); }
 		@Override
-		public KEY_TYPE FIRST_KEY() { return s.FIRST_KEY(); }
+		public KEY_TYPE GET_FIRST_KEY() { return s.GET_FIRST_KEY(); }
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() { throw new UnsupportedOperationException(); }
+		public KEY_TYPE REMOVE_FIRST_KEY() { throw new UnsupportedOperationException(); }
 		@Override
-		public KEY_TYPE LAST_KEY() { return s.LAST_KEY(); }
+		public KEY_TYPE GET_LAST_KEY() { return s.GET_LAST_KEY(); }
 		@Override
-		public KEY_TYPE POLL_LAST_KEY() { throw new UnsupportedOperationException(); }
+		public KEY_TYPE REMOVE_LAST_KEY() { throw new UnsupportedOperationException(); }
 	}
 	
 #endif
@@ -649,6 +655,10 @@ public class SETS
 			s = c;
 		}
 		
+		@Override
+		public void addFirst(KEY_TYPE o) { synchronized(mutex) { s.addFirst(o); } }
+		@Override
+		public void addLast(KEY_TYPE o) { synchronized(mutex) { s.addLast(o); } }
 		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { synchronized(mutex) { return s.addAndMoveToFirst(o); } }
 		@Override
@@ -660,17 +670,19 @@ public class SETS
 		@Override
 		public BI_ITERATOR KEY_GENERIC_TYPE iterator() { synchronized(mutex) { return s.iterator(); } }
 		@Override
+		public BI_ITERATOR KEY_GENERIC_TYPE reverseIterator() { synchronized(mutex) { return s.reverseIterator(); } }
+		@Override
 		public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) { synchronized(mutex) { return s.iterator(fromElement); } }
 		@Override
 		public ORDERED_SET KEY_GENERIC_TYPE copy() { synchronized(mutex) { return s.copy(); } }
 		@Override
-		public KEY_TYPE FIRST_KEY() { synchronized(mutex) { return s.FIRST_KEY(); } }
+		public KEY_TYPE GET_FIRST_KEY() { synchronized(mutex) { return s.GET_FIRST_KEY(); } }
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() { synchronized(mutex) { return s.POLL_FIRST_KEY(); } }
+		public KEY_TYPE REMOVE_FIRST_KEY() { synchronized(mutex) { return s.REMOVE_FIRST_KEY(); } }
 		@Override
-		public KEY_TYPE LAST_KEY() { synchronized(mutex) { return s.LAST_KEY(); } }
+		public KEY_TYPE GET_LAST_KEY() { synchronized(mutex) { return s.GET_LAST_KEY(); } }
 		@Override
-		public KEY_TYPE POLL_LAST_KEY() { synchronized(mutex) { return s.POLL_LAST_KEY(); } }
+		public KEY_TYPE REMOVE_LAST_KEY() { synchronized(mutex) { return s.REMOVE_LAST_KEY(); } }
 	}
 	
 #endif
@@ -56,6 +56,9 @@ import speiger.src.collections.PACKAGE.sets.SET;
 import speiger.src.collections.PACKAGE.utils.SETS;
 #endif
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+#if ORDERED_MAP_FEATURE
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
+#endif
 #if !SAME_TYPE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_UNARY_OPERATOR;
 #endif
@@ -553,6 +556,10 @@ public class MAPS
 		@Override
 		public VALUE_TYPE putAndMoveToLast(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
 		@Override
+		public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
+		@Override
 		public boolean moveToFirst(KEY_TYPE key) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean moveToLast(KEY_TYPE key) { throw new UnsupportedOperationException(); }
@@ -573,13 +580,25 @@ public class MAPS
 		@Override
 		public VALUE_TYPE LAST_ENTRY_VALUE() { return map.LAST_ENTRY_VALUE(); }
 		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() { return map.firstEntry(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() { return map.lastEntry(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() { throw new UnsupportedOperationException(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() { throw new UnsupportedOperationException(); }
+		@Override
 		public ORDERED_MAP KEY_VALUE_GENERIC_TYPE copy() { return map.copy(); }
 		@Override
 		public ORDERED_SET KEY_GENERIC_TYPE keySet() { 
 			if(keys == null) keys = SETS.unmodifiable(map.keySet()); 
 			return (ORDERED_SET KEY_GENERIC_TYPE)keys;
 		}
-				
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
+			if(values == null) values = VALUE_COLLECTIONS.unmodifiable(map.values());
+			return (VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE)values;
+		}
 		@Override
 		public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 			if(entrySet == null) entrySet = new UnmodifyableOrderedEntrySetKV_BRACES(map.ENTRY_SET());
@@ -736,6 +755,10 @@ public class MAPS
 			set = c;
 		}
 		
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -749,15 +772,17 @@ public class MAPS
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() { return ObjectIterators.unmodifiable(set.iterator()); }
 		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() { return ObjectIterators.unmodifiable(set.reverseIterator()); }
+		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator(MAP.Entry KEY_VALUE_GENERIC_TYPE fromElement) { return ObjectIterators.unmodifiable(set.iterator(fromElement)); }
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() { return set.first(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() { return set.getFirst(); }
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() { throw new UnsupportedOperationException(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() { throw new UnsupportedOperationException(); }
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() { return set.last(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() { return set.getLast(); }
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() { throw new UnsupportedOperationException(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() { throw new UnsupportedOperationException(); }
 	}
 	
 #endif
@@ -938,6 +963,10 @@ public class MAPS
 		@Override
 		public VALUE_TYPE putAndMoveToLast(KEY_TYPE key, VALUE_TYPE value) { synchronized(mutex) { return map.putAndMoveToLast(key, value); } }
 		@Override
+		public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) { synchronized(mutex) { return map.putFirst(key, value); } }
+		@Override
+		public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) { synchronized(mutex) { return map.putLast(key, value); } }
+		@Override
 		public boolean moveToFirst(KEY_TYPE key) { synchronized(mutex) { return map.moveToFirst(key); } }
 		@Override
 		public boolean moveToLast(KEY_TYPE key) { synchronized(mutex) { return map.moveToLast(key); } }
@@ -958,13 +987,25 @@ public class MAPS
 		@Override
 		public VALUE_TYPE LAST_ENTRY_VALUE() { synchronized(mutex) { return map.LAST_ENTRY_VALUE(); } }
 		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() { synchronized(mutex) { return map.firstEntry(); } }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() { synchronized(mutex) { return map.lastEntry(); } }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() { synchronized(mutex) { return map.pollFirstEntry(); } }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() { synchronized(mutex) { return map.pollLastEntry(); } }
+		@Override
 		public ORDERED_MAP KEY_VALUE_GENERIC_TYPE copy() { synchronized(mutex) { return map.copy(); } }
 		@Override
 		public ORDERED_SET KEY_GENERIC_TYPE keySet() {
 			if(keys == null) keys = SETS.synchronize(map.keySet(), mutex);
 			return (ORDERED_SET KEY_GENERIC_TYPE)keys;
 		}
-		
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
+			if(values == null) values = VALUE_COLLECTIONS.synchronize(map.values(), mutex);
+			return (VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE)values;
+		}
 		@Override
 		public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 			if(entrySet == null) entrySet = ObjectSets.synchronize(map.ENTRY_SET(), mutex);
@@ -1,16 +1,29 @@
 package speiger.src.testers.PACKAGE.builder;

+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;

 import com.google.common.collect.testing.AbstractTester;
+import com.google.common.collect.testing.FeatureSpecificTestSuiteBuilder;
 import com.google.common.collect.testing.Helpers;
+import com.google.common.collect.testing.OneSizeTestContainerGenerator;
+import com.google.common.collect.testing.SampleElements;
 import com.google.common.collect.testing.features.CollectionFeature;
+import com.google.common.collect.testing.features.Feature;

 import junit.framework.TestSuite;
+import speiger.src.collections.PACKAGE.collections.ITERABLE;
+import speiger.src.collections.PACKAGE.lists.ARRAY_LIST;
+import speiger.src.collections.PACKAGE.lists.LIST;
+import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
+import speiger.src.collections.PACKAGE.utils.LISTS;
 import speiger.src.testers.PACKAGE.generators.TEST_ORDERED_SET_GENERATOR;
 import speiger.src.testers.PACKAGE.tests.set.FILE_KEY_TYPEOrderedSetMoveTester;
 import speiger.src.testers.PACKAGE.tests.set.FILE_KEY_TYPEOrderedSetIterationTester;
 import speiger.src.testers.PACKAGE.tests.set.FILE_KEY_TYPEOrderedSetNavigationTester;
+import speiger.src.testers.PACKAGE.utils.SAMPLE_ELEMENTS;
+import speiger.src.testers.utils.SpecialFeature;

@SuppressWarnings("javadoc")
 public class ORDERED_SET_TEST_BUILDER KEY_GENERIC_TYPE extends SET_TEST_BUILDER KEY_GENERIC_TYPE {
@@ -35,4 +48,68 @@ public class ORDERED_SET_TEST_BUILDER KEY_GENERIC_TYPE extends SET_TEST_BUILDER
 #endignore
 		return super.createTestSuite();
 	}
+	
+	@Override
+	protected List<TestSuite> createDerivedSuites(
+			FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Collection<CLASS_TYPE>, CLASS_TYPE>> parentBuilder) {
+		List<TestSuite> derivedSuites = super.createDerivedSuites(parentBuilder);
+
+		if (!parentBuilder.getFeatures().contains(SpecialFeature.REVERSE)) {
+			derivedSuites.add(createReverseSuite(parentBuilder));
+		}
+
+		return derivedSuites;
+	}
+
+	private TestSuite createReverseSuite(FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Collection<CLASS_TYPE>, CLASS_TYPE>> parentBuilder) {
+		TEST_ORDERED_SET_GENERATOR KEY_GENERIC_TYPE delegate = (TEST_ORDERED_SET_GENERATOR KEY_GENERIC_TYPE) parentBuilder.getSubjectGenerator().getInnerGenerator();
+
+		List<Feature<?>> features = new ArrayList<>();
+		features.add(SpecialFeature.REVERSE);
+		features.addAll(parentBuilder.getFeatures());
+		features.remove(SpecialFeature.COPYING);
+		features.remove(SpecialFeature.CHILDREN_COPY);
+		
+		return ORDERED_SET_TEST_BUILDER.using(new TEST_ORDERED_SET_GENERATOR KEY_GENERIC_TYPE() {
+			@Override
+			public SampleElements<CLASS_TYPE> samples() {
+				return delegate.samples();
+			}
+			
+			@Override
+			public SAMPLE_ELEMENTS KEY_GENERIC_TYPE getSamples() {
+				return delegate.getSamples();
+			}
+
+			@Override
+			public ITERABLE KEY_GENERIC_TYPE order(LIST KEY_GENERIC_TYPE insertionOrder) {
+				return insertionOrder;
+			}
+
+			@Override
+			public Iterable<CLASS_TYPE> order(List<CLASS_TYPE> insertionOrder) {
+				return insertionOrder;
+			}
+			
+#if !TYPE_OBJECT
+			@Override
+			public ORDERED_SET KEY_GENERIC_TYPE create(KEY_TYPE... elements) {
+				LIST KEY_GENERIC_TYPE list = new ARRAY_LISTBRACES(elements);
+				LISTS.reverse(list);
+				return delegate.create(list.TO_ARRAY()).reversed();
+			}
+			
+#endif
+			@Override
+			public ORDERED_SET KEY_GENERIC_TYPE create(Object... elements) {
+				LIST KEY_GENERIC_TYPE list = new ARRAY_LISTBRACES();
+				for (Object e : elements) {
+					list.add(CLASS_TO_KEY(e));
+				}
+				LISTS.reverse(list);
+				return delegate.create(list.toArray()).reversed();
+			}
+		}).named(parentBuilder.getName() + " reversing").withFeatures(features)
+				.suppressing(parentBuilder.getSuppressedTests()).createTestSuite();
+	}
 }
@@ -238,21 +238,17 @@ public class MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MapTestSuiteBuilder
 	private static Set<Feature<?>> computeEntrySetFeatures(Set<Feature<?>> mapFeatures) {
 		Set<Feature<?>> entrySetFeatures = MapTestSuiteBuilder.computeCommonDerivedCollectionFeatures(mapFeatures);
 #ignore
-		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_ENTRY_QUERIES)) {
-			entrySetFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
-		}
-		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) {
-			entrySetFeatures.add(SpecialFeature.COPYING);
-		}
-		else {
-			entrySetFeatures.remove(SpecialFeature.COPYING);
-		}
-		if(mapFeatures.contains(SpecialFeature.MODIFIABLE)) {
-			entrySetFeatures.add(SpecialFeature.MODIFIABLE);
-		}
-		else {
-			entrySetFeatures.remove(SpecialFeature.MODIFIABLE);
-		}
+		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_ENTRY_QUERIES)) entrySetFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
+
+		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) entrySetFeatures.add(SpecialFeature.COPYING);
+		else entrySetFeatures.remove(SpecialFeature.COPYING);
+		
+		if(mapFeatures.contains(SpecialFeature.MODIFIABLE)) entrySetFeatures.add(SpecialFeature.MODIFIABLE);
+		else entrySetFeatures.remove(SpecialFeature.MODIFIABLE);
+		
+		if(mapFeatures.contains(SpecialFeature.REVERSE)) entrySetFeatures.add(SpecialFeature.REVERSE);
+		else entrySetFeatures.remove(SpecialFeature.REVERSE);
+		
 		entrySetFeatures.add(SpecialFeature.MAP_ENTRY);
 #endignore
 		return entrySetFeatures;
@@ -262,23 +258,17 @@ public class MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MapTestSuiteBuilder
 		Set<Feature<?>> keySetFeatures = MapTestSuiteBuilder.computeCommonDerivedCollectionFeatures(mapFeatures);
 #ignore
 		keySetFeatures.add(CollectionFeature.SUBSET_VIEW);
-		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_KEYS)) {
-			keySetFeatures.add(CollectionFeature.ALLOWS_NULL_VALUES);
-		} else if (mapFeatures.contains(MapFeature.ALLOWS_NULL_KEY_QUERIES)) {
-			keySetFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
-		}
-		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) {
-			keySetFeatures.add(SpecialFeature.COPYING);
-		}
-		else {
-			keySetFeatures.remove(SpecialFeature.COPYING);
-		}
-		if(mapFeatures.contains(SpecialFeature.MODIFIABLE)) {
-			keySetFeatures.add(SpecialFeature.MODIFIABLE);
-		}
-		else {
-			keySetFeatures.remove(SpecialFeature.MODIFIABLE);
-		}
+		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_KEYS)) keySetFeatures.add(CollectionFeature.ALLOWS_NULL_VALUES);
+		else if (mapFeatures.contains(MapFeature.ALLOWS_NULL_KEY_QUERIES)) keySetFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
+		
+		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) keySetFeatures.add(SpecialFeature.COPYING);
+		else keySetFeatures.remove(SpecialFeature.COPYING);
+		
+		if(mapFeatures.contains(SpecialFeature.MODIFIABLE)) keySetFeatures.add(SpecialFeature.MODIFIABLE);
+		else keySetFeatures.remove(SpecialFeature.MODIFIABLE);
+		
+		if(mapFeatures.contains(SpecialFeature.REVERSE)) keySetFeatures.add(SpecialFeature.REVERSE);
+		else keySetFeatures.remove(SpecialFeature.REVERSE);
 #endignore
 		return keySetFeatures;
 	}
@@ -287,18 +277,15 @@ public class MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MapTestSuiteBuilder
 	private static Set<Feature<?>> computeValuesCollectionFeatures(Set<Feature<?>> mapFeatures) {
 		Set<Feature<?>> valuesCollectionFeatures = MapTestSuiteBuilder.computeCommonDerivedCollectionFeatures(mapFeatures);
 #ignore
-		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_VALUE_QUERIES)) {
-			valuesCollectionFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
-		}
-		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_VALUES)) {
-			valuesCollectionFeatures.add(CollectionFeature.ALLOWS_NULL_VALUES);
-		}
-		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) {
-			valuesCollectionFeatures.add(SpecialFeature.COPYING);
-		}
-		else {
-			valuesCollectionFeatures.remove(SpecialFeature.COPYING);
-		}
+		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_VALUE_QUERIES)) valuesCollectionFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
+		
+		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_VALUES)) valuesCollectionFeatures.add(CollectionFeature.ALLOWS_NULL_VALUES);
+		
+		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) valuesCollectionFeatures.add(SpecialFeature.COPYING); 
+		else valuesCollectionFeatures.remove(SpecialFeature.COPYING);
+		
+		if(mapFeatures.contains(SpecialFeature.REVERSE)) valuesCollectionFeatures.add(SpecialFeature.REVERSE);
+		else valuesCollectionFeatures.remove(SpecialFeature.REVERSE);
 #endignore
 		return valuesCollectionFeatures;
 	}
@@ -1,9 +1,14 @@
 package speiger.src.testers.PACKAGE.builder.maps;

+import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;

 import com.google.common.collect.testing.AbstractTester;
+import com.google.common.collect.testing.FeatureSpecificTestSuiteBuilder;
+import com.google.common.collect.testing.OneSizeTestContainerGenerator;
 import com.google.common.collect.testing.features.CollectionFeature;
+import com.google.common.collect.testing.features.Feature;

 import junit.framework.TestSuite;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
@@ -12,14 +17,17 @@ import speiger.src.testers.PACKAGE.builder.SET_TEST_BUILDER;
 import speiger.src.testers.PACKAGE.generators.TEST_ORDERED_SET_GENERATOR;
 import speiger.src.testers.PACKAGE.generators.TEST_SET_GENERATOR;
 import speiger.src.testers.PACKAGE.generators.maps.TEST_ORDERED_MAP_GENERATOR;
+import speiger.src.testers.PACKAGE.impl.maps.DERIVED_MAP_GENERATORS;
 import speiger.src.testers.PACKAGE.tests.maps.FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapMoveTester;
 import speiger.src.testers.PACKAGE.tests.maps.FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapNavigationTester;
+import speiger.src.testers.PACKAGE.tests.maps.FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapPutTester;
 #if !TYPE_OBJECT
 import speiger.src.testers.objects.builder.ObjectSetTestSuiteBuilder;
 import speiger.src.testers.objects.generators.TestObjectSetGenerator;
 import speiger.src.testers.objects.builder.ObjectOrderedSetTestSuiteBuilder;
 import speiger.src.testers.objects.generators.TestObjectOrderedSetGenerator;
 #endif
+import speiger.src.testers.utils.SpecialFeature;

@SuppressWarnings("javadoc")
 public class ORDERED_MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE
@@ -34,6 +42,7 @@ public class ORDERED_MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MAP_TEST_BU
 		List<Class<? extends AbstractTester>> testers = super.getTesters();
 		testers.add(FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapMoveTester.class);
 		testers.add(FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapNavigationTester.class);
+		testers.add(FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapPutTester.class);
 		return testers;
 	}
 	
@@ -45,6 +54,15 @@ public class ORDERED_MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MAP_TEST_BU
 		return super.createTestSuite();
 	}
 	
+	@Override
+	protected List<TestSuite> createDerivedSuites(FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Map<CLASS_TYPE, CLASS_VALUE_TYPE>, Map.Entry<CLASS_TYPE, CLASS_VALUE_TYPE>>> parentBuilder) {
+		List<TestSuite> derivedSuites = super.createDerivedSuites(parentBuilder);
+		if (!parentBuilder.getFeatures().contains(SpecialFeature.REVERSE)) {
+			derivedSuites.add(createReverseSuite(parentBuilder));
+		}
+		return derivedSuites;
+	}
+	
 	protected ObjectSetTestSuiteBuilder<MAP.Entry KEY_VALUE_GENERIC_TYPE> createDerivedEntrySetSuite(TestObjectSetGenerator<MAP.Entry KEY_VALUE_GENERIC_TYPE> entrySetGenerator) {
 		return ObjectOrderedSetTestSuiteBuilder.using((TestObjectOrderedSetGenerator<MAP.Entry KEY_VALUE_GENERIC_TYPE>)entrySetGenerator);
 	}
@@ -52,4 +70,17 @@ public class ORDERED_MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MAP_TEST_BU
 	protected SET_TEST_BUILDER KEY_GENERIC_TYPE createDerivedKeySetSuite(TEST_SET_GENERATOR KEY_GENERIC_TYPE generator) {
 		return ORDERED_SET_TEST_BUILDER.using((TEST_ORDERED_SET_GENERATOR KEY_GENERIC_TYPE)generator);
 	}
+	
+	private TestSuite createReverseSuite(FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Map<CLASS_TYPE, CLASS_VALUE_TYPE>, Map.Entry<CLASS_TYPE, CLASS_VALUE_TYPE>>> parentBuilder) {
+		TEST_ORDERED_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE delegate = (TEST_ORDERED_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE) parentBuilder.getSubjectGenerator().getInnerGenerator();
+
+		List<Feature<?>> features = new ArrayList<>();
+		features.add(SpecialFeature.REVERSE);
+		features.addAll(parentBuilder.getFeatures());
+		features.remove(SpecialFeature.COPYING);
+		features.remove(SpecialFeature.CHILDREN_COPY);
+		return ORDERED_MAP_TEST_BUILDER.using(new DERIVED_MAP_GENERATORS.ReverseTestOrderedMapGeneratorKV_BRACES(delegate))
+				.named(parentBuilder.getName() + " reversed").withFeatures(features)
+				.suppressing(parentBuilder.getSuppressedTests()).createTestSuite();
+	}
 }
@@ -20,6 +20,7 @@ import speiger.src.collections.PACKAGE.maps.abstracts.ABSTRACT_MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP.Entry;
 import speiger.src.collections.PACKAGE.maps.interfaces.NAVIGABLE_MAP;
+import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.SORTED_MAP;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.sets.SET;
@@ -206,6 +207,22 @@ public class DERIVED_MAP_GENERATORS {
 		}
 	}
 	
+	public static class ReverseTestOrderedMapGenerator KEY_VALUE_GENERIC_TYPE extends MapGenerator KEY_VALUE_GENERIC_TYPE implements TEST_ORDERED_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE {
+		TEST_ORDERED_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE parent;
+		
+		public ReverseTestOrderedMapGenerator(TEST_ORDERED_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE parent) {
+			super(parent);
+			this.parent = parent;
+		}
+		
+		@Override
+		public ORDERED_MAP KEY_VALUE_GENERIC_TYPE create(Entry KEY_VALUE_GENERIC_TYPE... elements) {
+			ObjectList<Entry KEY_VALUE_GENERIC_TYPE> entries = new ObjectArrayList<Entry KEY_VALUE_GENERIC_TYPE>(elements);
+			ObjectLists.reverse(entries);
+			return ((ORDERED_MAP KEY_VALUE_GENERIC_TYPE)parent.create(entries.toArray(Entry[]::new))).reversed();
+		}
+	}
+	
 	public static class MapGenerator KEY_VALUE_GENERIC_TYPE implements TEST_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE
 	{
 		TEST_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE parent;
@@ -27,6 +27,8 @@ import speiger.src.collections.PACKAGE.maps.impl.concurrent.CONCURRENT_HASH_MAP;
 #if TYPE_OBJECT
 import speiger.src.collections.PACKAGE.maps.impl.misc.ENUM_MAP;
 import speiger.src.collections.PACKAGE.maps.impl.misc.LINKED_ENUM_MAP;
+import speiger.src.collections.PACKAGE.maps.impl.reference.REF_MAP;
+import speiger.src.collections.PACKAGE.maps.impl.reference.LINKED_REF_MAP;
 #endif

 import speiger.src.collections.PACKAGE.maps.impl.tree.RB_TREE_MAP;
@@ -134,6 +136,97 @@ public class MAP_CONSTRUCTOR_TESTS
 	}
 	
 #if TYPE_OBJECT
+	public static class RefMap extends FILE_KEY_TYPE2FILE_VALUE_TYPEMapConstructorTester KEY_VALUE_STRING_GENERIC_TYPE
+	{
+		public RefMap() {
+			setSimpleConstructor(REF_MAP::new);
+			setSizeConstructor(REF_MAP::new);
+			setPArrayConstructor(REF_MAP::new);
+#if !TYPE_OBJECT || !VALUE_OBJECT
+			setArrayConstructor(REF_MAP::new);
+#endif
+			setPMapConstructor(REF_MAP::new);
+			setMapConstructor(REF_MAP::new);
+		}
+	
+		@Test
+		public void testWrongLoadFactorSize() {
+			setSizeConstructor(T -> new REF_MAP KEY_VALUE_STRING_GENERIC_TYPE(T, 0F));
+			try {
+				testSizeConstructor_smallSize();
+				fail("A Constructor using a 0 LoadFactor should error");
+			} catch(IllegalStateException e) {}
+		
+			setSizeConstructor(T -> new REF_MAP KEY_VALUE_STRING_GENERIC_TYPE(T, 1F));
+			try {
+				testSizeConstructor_smallSize();
+				fail("A Constructor using a 1 LoadFactor should error");
+			} catch(IllegalStateException e) {}
+		}
+	
+#if TYPE_OBJECT
+		@Override
+		protected String[] createKeyElements() {
+			return Arrays.copyOfRange(StringSortTest.NAMES, 0, 100);
+		}
+		
+#endif
+#if VALUE_OBJECT
+		@Override
+		protected String[] createValueElements() {
+			return Arrays.copyOfRange(StringSortTest.NAMES, 100, 200);
+		}
+		
+#endif
+	}
+	
+	public static class LinkedRefMap extends FILE_KEY_TYPE2FILE_VALUE_TYPEMapConstructorTester KEY_VALUE_STRING_GENERIC_TYPE
+	{
+		public LinkedRefMap() {
+			setSimpleConstructor(LINKED_REF_MAP::new);
+			setSizeConstructor(LINKED_REF_MAP::new);
+			setPArrayConstructor(LINKED_REF_MAP::new);
+#if !TYPE_OBJECT || !VALUE_OBJECT
+			setArrayConstructor(LINKED_REF_MAP::new);
+#endif
+			setPMapConstructor(LINKED_REF_MAP::new);
+			setMapConstructor(LINKED_REF_MAP::new);
+		}
+		
+		@Test
+		public void testWrongLoadFactorSize() {
+			setSizeConstructor(T -> new LINKED_REF_MAP KEY_VALUE_STRING_GENERIC_TYPE(T, 0F));
+			try {
+				testSizeConstructor_smallSize();
+				fail("A Constructor using a 0 LoadFactor should error");
+			} catch(IllegalStateException e) {
+			}
+			
+			setSizeConstructor(T -> new LINKED_REF_MAP KEY_VALUE_STRING_GENERIC_TYPE(T, 1F));
+			try {
+				testSizeConstructor_smallSize();
+				fail("A Constructor using a 1 LoadFactor should error");
+			} catch(IllegalStateException e) {
+			}
+		}
+		
+#if TYPE_OBJECT
+		@Override
+		protected String[] createKeyElements() {
+			return Arrays.copyOfRange(StringSortTest.NAMES, 0, 100);
+		}
+		
+#endif
+#if VALUE_OBJECT
+		@Override
+		protected String[] createValueElements() {
+			return Arrays.copyOfRange(StringSortTest.NAMES, 100, 200);
+		}
+		
+#endif
+	}
+	
+	
 #if VALUE_OBJECT
 	public static class EnumMap extends FILE_KEY_TYPE2FILE_VALUE_TYPEMapConstructorTester<AnEnum, String>
 #else
@@ -26,6 +26,15 @@ public class FILE_KEY_TYPECollectionForEachTester KEY_GENERIC_TYPE extends ABSTR
 		HELPERS.assertContentsAnyOrder(elements, createSamplesArray());
 	}

+#ignore
+	@CollectionFeature.Require(absent = KNOWN_ORDER)
+	public void testIndexedForEachUnknownOrder() {
+#endignore
+		LIST KEY_GENERIC_TYPE elements = new ARRAY_LISTBRACES();
+		collection.forEachIndexed((K, V) -> elements.add(V));
+		HELPERS.assertContentsAnyOrder(elements, createSamplesArray());
+	}
+	
 #ignore
@CollectionFeature.Require(absent = KNOWN_ORDER)
 	public void testForEachExtraUnknownOrder() {
@@ -44,6 +53,15 @@ public class FILE_KEY_TYPECollectionForEachTester KEY_GENERIC_TYPE extends ABSTR
 		assertEquals("Different ordered iteration", HELPERS.copyToList(getOrderedElements()), elements);
 	}

+#ignore
+	@CollectionFeature.Require(KNOWN_ORDER)
+	public void testIndexedForEachKnownOrder() {
+#endignore
+		LIST KEY_GENERIC_TYPE elements = new ARRAY_LISTBRACES();
+		collection.forEachIndexed((K, V) -> elements.add(V));
+		assertEquals("Different ordered iteration", HELPERS.copyToList(getOrderedElements()), elements);
+	}
+	
 #ignore
 	@CollectionFeature.Require(KNOWN_ORDER)
 	public void testForEachExtraKnownOrder() {
@@ -4,6 +4,12 @@ package speiger.src.testers.PACKAGE.tests.iterable;
 import java.util.Objects;

 #endif
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#else
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
+
 import org.junit.Ignore;

 import com.google.common.collect.testing.features.CollectionSize;
@@ -27,17 +33,17 @@ public class FILE_KEY_TYPEIterableFindFirstTester KEY_GENERIC_TYPE extends ABSTR
 	@CollectionSize.Require(absent = CollectionSize.ZERO)
 #endignore
 	public void testIterableFindFirst_FindFirstElements() {
-		assertEquals("First Element should be found", e0(), container.findFirst(T -> KEY_EQUALS(T, e0())));
+		assertEquals("First Element should be found", e0(), container.findFirst(T -> KEY_EQUALS(T, e0())).SUPPLY_GET());
 	}
 	
 	public void testIterableFindFirst_FindNothing() {
-		assertEquals("No element should be found", EMPTY_KEY_VALUE, container.findFirst(T -> KEY_EQUALS(T, e4())));
+		assertEquals("No element should be found", OPTIONAL.empty(), container.findFirst(T -> KEY_EQUALS(T, e4())));
 	}
 	
 #ignore
 	@CollectionSize.Require(CollectionSize.SEVERAL)
 #endignore
 	public void testIterableFindFirst_FindLastElement() {
-		assertEquals("Last Element should be found", e2(), container.findFirst(T -> KEY_EQUALS(T, e2())));
+		assertEquals("Last Element should be found", e2(), container.findFirst(T -> KEY_EQUALS(T, e2())).SUPPLY_GET());
 	}
 }
@@ -3,9 +3,16 @@ package speiger.src.testers.PACKAGE.tests.iterable;
 #if TYPE_OBJECT
 import java.util.Objects;

+#endif
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#else
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
 #endif
 import org.junit.Ignore;

+import com.google.common.collect.testing.features.CollectionSize;
+
 import speiger.src.testers.PACKAGE.tests.base.ABSTRACT_COLLECTION_TESTER;

@Ignore
@@ -29,7 +36,7 @@ public class FILE_KEY_TYPEIterableReduceTester KEY_GENERIC_TYPE extends ABSTRACT
 	}
 	
 	public void testIterableReduce() {
-		assertEquals("The sum of the collection should match", getSum(), collection.reduce(this::sum));
+		assertEquals("The sum of the collection should match", size == CollectionSize.ZERO ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(getSum()), collection.reduce(this::sum));
 	}
 	
 	public void testIterableExtraReduce() {
@@ -27,6 +27,7 @@ public class FILE_KEY_TYPE2FILE_VALUE_TYPEMapContainsTester KEY_VALUE_GENERIC_TY

 #ignore
 	@CollectionSize.Require(absent = ZERO)
+	@SuppressWarnings("unlikely-arg-type")
 #endignore
 	public void testContainsObject_yes() {
 		assertTrue("contains(present) should return true", getMap().ENTRY_SET().contains(new AbstractMap.SimpleEntry<>(e0())));
@@ -36,6 +37,7 @@ public class FILE_KEY_TYPE2FILE_VALUE_TYPEMapContainsTester KEY_VALUE_GENERIC_TY
 		assertFalse("contains(notPresent) should return false", getMap().ENTRY_SET().contains(e3()));
 	}
 	
+	@SuppressWarnings("unlikely-arg-type")
 	public void testContainsObject_no() {
 		assertFalse("contains(notPresent) should return false", getMap().ENTRY_SET().contains(new AbstractMap.SimpleEntry<>(e3())));
 	}
@@ -136,6 +136,7 @@ public class FILE_KEY_TYPE2FILE_VALUE_TYPEMapRemoveEntryTester KEY_VALUE_GENERIC
 #ignore
 	@CollectionSize.Require(ONE)
 	@MapFeature.Require(SUPPORTS_REMOVE)
+	@SuppressWarnings("unlikely-arg-type")
 #endignore
 	public void testRemove_supportedObjectEntryPresent() {
 		assertTrue(getMap().ENTRY_SET().remove(new AbstractMap.SimpleEntry<>(e0())));
@@ -154,6 +155,7 @@ public class FILE_KEY_TYPE2FILE_VALUE_TYPEMapRemoveEntryTester KEY_VALUE_GENERIC
 #ignore
 	@CollectionSize.Require(ONE)
 	@MapFeature.Require(SUPPORTS_REMOVE)
+	@SuppressWarnings("unlikely-arg-type")
 #endignore
 	public void testRemove_supportedObjectEntryMissing() {
 		assertFalse(getMap().ENTRY_SET().remove(new AbstractMap.SimpleEntry<>(e3())));
@@ -0,0 +1,118 @@
+package speiger.src.testers.PACKAGE.tests.maps;
+
+#ignore
+import static com.google.common.collect.testing.features.CollectionSize.ZERO;
+import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_PUT;
+import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_REMOVE;
+import static org.junit.Assert.assertNotEquals;
+#endignore
+
+import com.google.common.collect.testing.features.CollectionSize;
+import com.google.common.collect.testing.features.MapFeature;
+
+import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
+import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
+import speiger.src.collections.objects.lists.ObjectList;
+import speiger.src.testers.PACKAGE.tests.base.maps.ABSTRACT_MAP_TESTER;
+import speiger.src.testers.objects.utils.ObjectHelpers;
+
+@SuppressWarnings("javadoc")
+public class FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapPutTester KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP_TESTER KEY_VALUE_GENERIC_TYPE
+{
+	private ORDERED_MAP KEY_VALUE_GENERIC_TYPE orderedMap;
+	private ObjectList<MAP.Entry KEY_VALUE_GENERIC_TYPE> values;
+	private KEY_TYPE a;
+	private VALUE_TYPE aValue;
+	
+	@Override
+	public void setUp() throws Exception {
+		super.setUp();
+		orderedMap = (ORDERED_MAP KEY_VALUE_GENERIC_TYPE)getMap();
+		values = ObjectHelpers.copyToList(getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
+		if (values.size() >= 1) {
+			a = values.get(0).ENTRY_KEY();
+			aValue = values.get(0).ENTRY_VALUE();
+		}
+	}
+	
+#ignore
+	@MapFeature.Require(SUPPORTS_PUT)
+	@CollectionSize.Require(absent = ZERO)
+#endignore
+	public void testPutFirst() {
+		assertEquals(aValue, orderedMap.putFirst(a, v3()));
+		assertNotEquals(v3(), orderedMap.FIRST_ENTRY_VALUE());
+		assertEquals(orderedMap.getDefaultReturnValue(), orderedMap.putFirst(k4(), v4()));
+		assertEquals(v4(), orderedMap.FIRST_ENTRY_VALUE());
+		assertEquals(e4(), orderedMap.firstEntry());
+	}
+	
+
+#ignore
+	@MapFeature.Require(SUPPORTS_PUT)
+	@CollectionSize.Require(absent = ZERO)
+#endignore
+	public void testPutLast() {
+		assertEquals(aValue, orderedMap.putLast(a, v3()));
+		assertNotEquals(v3(), orderedMap.LAST_ENTRY_VALUE());
+		assertEquals(orderedMap.getDefaultReturnValue(), orderedMap.putLast(k4(), v4()));
+		assertEquals(v4(), orderedMap.LAST_ENTRY_VALUE());
+		assertEquals(e4(), orderedMap.lastEntry());
+	}
+	
+#ignore
+	@MapFeature.Require(SUPPORTS_REMOVE)
+	@CollectionSize.Require(CollectionSize.ONE)
+#endignore
+	public void testPollFirst() {
+		assertFalse(orderedMap.isEmpty());
+		assertEquals(e0(), orderedMap.pollFirstEntry());
+		assertTrue(orderedMap.isEmpty());
+	}
+	
+#ignore
+	@MapFeature.Require(SUPPORTS_REMOVE)
+	@CollectionSize.Require(CollectionSize.ONE)
+#endignore
+	public void testPollLast() {
+		assertFalse(orderedMap.isEmpty());
+		assertEquals(e0(), orderedMap.pollLastEntry());
+		assertTrue(orderedMap.isEmpty());
+	}
+	
+#ignore
+	@MapFeature.Require(absent = SUPPORTS_PUT)
+#endignore
+	public void testUnsupportedPutFirst() {
+		try { orderedMap.putFirst(a, aValue); }
+		catch (UnsupportedOperationException tolerated) {}
+		expectUnchanged();
+	}
+	
+#ignore
+	@MapFeature.Require(absent = SUPPORTS_PUT)
+#endignore
+	public void testUnsupportedPutLast() {
+		try { orderedMap.putLast(a, aValue); }
+		catch (UnsupportedOperationException tolerated) {}
+		expectUnchanged();
+	}
+	
+#ignore
+	@MapFeature.Require(absent = SUPPORTS_REMOVE)
+#endignore
+	public void testUnsupportedPollFirst() {
+		try { orderedMap.pollFirstEntry(); }
+		catch (UnsupportedOperationException tolerated) {}
+		expectUnchanged();
+	}
+	
+#ignore
+	@MapFeature.Require(absent = SUPPORTS_REMOVE)
+#endignore
+	public void testUnsupportedPollLast() {
+		try { orderedMap.pollFirstEntry(); }
+		catch (UnsupportedOperationException tolerated) {}
+		expectUnchanged();
+	}
+}
@@ -2,6 +2,11 @@ package speiger.src.testers.PACKAGE.tests.queue.iterators;

 #if TYPE_OBJECT
 import java.util.Objects;
+#endif
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#else
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;

 #endif
 import org.junit.Ignore;
@@ -27,17 +32,17 @@ public class FILE_KEY_TYPEQueueFindFirstTester KEY_GENERIC_TYPE extends ABSTRACT
 	@CollectionSize.Require(absent = CollectionSize.ZERO)
 #endignore
 	public void testQueueFindFirst_FindFirstElements() {
-		assertEquals("First Element should be found", e0(), queue.findFirst(T -> KEY_EQUALS(T, e0())));
+		assertEquals("First Element should be found", e0(), queue.findFirst(T -> KEY_EQUALS(T, e0())).SUPPLY_GET());
 	}
 	
 	public void testQueueFindFirst_FindNothing() {
-		assertEquals("No element should be found", EMPTY_KEY_VALUE, queue.findFirst(T -> KEY_EQUALS(T, e4())));
+		assertEquals("No element should be found", OPTIONAL.empty(), queue.findFirst(T -> KEY_EQUALS(T, e4())));
 	}
 	
 #ignore
 	@CollectionSize.Require(CollectionSize.SEVERAL)
 #endignore
 	public void testQueueFindFirst_FindLastElement() {
-		assertEquals("Last Element should be found", e2(), queue.findFirst(T -> KEY_EQUALS(T, e2())));
+		assertEquals("Last Element should be found", e2(), queue.findFirst(T -> KEY_EQUALS(T, e2())).SUPPLY_GET());
 	}
 }
@@ -3,10 +3,16 @@ package speiger.src.testers.PACKAGE.tests.queue.iterators;
 #if TYPE_OBJECT
 import java.util.Objects;

+#endif
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#else
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
 #endif
 import org.junit.Ignore;

 import speiger.src.testers.PACKAGE.tests.base.ABSTRACT_QUEUE_TESTER;
+import com.google.common.collect.testing.features.CollectionSize;

@Ignore
@SuppressWarnings("javadoc")
@@ -29,7 +35,7 @@ public class FILE_KEY_TYPEQueueReduceTester KEY_GENERIC_TYPE extends ABSTRACT_QU
 	}
 	
 	public void testQueueReduce() {
-		assertEquals("The sum of the queue should match", getSum(), queue.reduce(this::sum));
+		assertEquals("The sum of the queue should match", size == CollectionSize.ZERO ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(getSum()), queue.reduce(this::sum));
 	}
 	
 	public void testQueueExtraReduce() {
@@ -45,10 +45,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testaddMoveToFirstMissing()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertEquals(true, orderedSet.addAndMoveToFirst(e4()));
-		assertNotEquals(a, orderedSet.FIRST_KEY());
-		assertEquals(e4(), orderedSet.FIRST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
+		assertEquals(e4(), orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -57,10 +57,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testaddMoveToFirstPreset()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertEquals(false, orderedSet.addAndMoveToFirst(c));
-		assertNotEquals(a, orderedSet.FIRST_KEY());
-		assertEquals(c, orderedSet.FIRST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
+		assertEquals(c, orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -69,10 +69,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testaddMoveToLastMissing()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertEquals(true, orderedSet.addAndMoveToLast(e4()));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(e4(), orderedSet.LAST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(e4(), orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -81,10 +81,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testaddMoveToLastPreset()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertEquals(false, orderedSet.addAndMoveToLast(a));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(a, orderedSet.LAST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(a, orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -93,9 +93,9 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveToFirstMissing()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertEquals(false, orderedSet.moveToFirst(e4()));
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -104,10 +104,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveToFirstPreset()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertEquals(true, orderedSet.moveToFirst(c));
-		assertNotEquals(a, orderedSet.FIRST_KEY());
-		assertEquals(c, orderedSet.FIRST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
+		assertEquals(c, orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -116,9 +116,9 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveToLastMissing()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertEquals(false, orderedSet.moveToLast(e4()));
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -127,10 +127,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveToLastPreset()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertEquals(true, orderedSet.moveToLast(a));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(a, orderedSet.LAST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(a, orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -139,10 +139,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveCenterToLast()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertTrue(orderedSet.moveToLast(e1()));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(e1(), orderedSet.LAST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(e1(), orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -151,10 +151,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveCenterToFirst()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertTrue(orderedSet.moveToFirst(e1()));
-		assertNotEquals(c, orderedSet.FIRST_KEY());
-		assertEquals(e1(), orderedSet.FIRST_KEY());
+		assertNotEquals(c, orderedSet.GET_FIRST_KEY());
+		assertEquals(e1(), orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -163,13 +163,13 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveForthAndBack()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertTrue(orderedSet.moveToLast(e0()));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(a, orderedSet.LAST_KEY());
-		assertNotEquals(a, orderedSet.FIRST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(a, orderedSet.GET_LAST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
 		assertTrue(orderedSet.moveToFirst(e0()));
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -178,13 +178,13 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveBackAndForth()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertTrue(orderedSet.moveToFirst(e2()));
-		assertNotEquals(a, orderedSet.FIRST_KEY());
-		assertEquals(c, orderedSet.FIRST_KEY());
-		assertNotEquals(c, orderedSet.LAST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
+		assertEquals(c, orderedSet.GET_FIRST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
 		assertTrue(orderedSet.moveToLast(e2()));
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -193,13 +193,13 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testAddForthAndBack()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertFalse(orderedSet.addAndMoveToLast(e0()));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(a, orderedSet.LAST_KEY());
-		assertNotEquals(a, orderedSet.FIRST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(a, orderedSet.GET_LAST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
 		assertFalse(orderedSet.addAndMoveToFirst(e0()));
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -208,13 +208,13 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testAddBackAndForth()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertFalse(orderedSet.addAndMoveToFirst(e2()));
-		assertNotEquals(a, orderedSet.FIRST_KEY());
-		assertEquals(c, orderedSet.FIRST_KEY());
-		assertNotEquals(c, orderedSet.LAST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
+		assertEquals(c, orderedSet.GET_FIRST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
 		assertFalse(orderedSet.addAndMoveToLast(e2()));
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -68,7 +68,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 		int polled = 0;
 		int expectedPolls = orderedSet.size();
 		while(polled < expectedPolls) {
-			orderedSet.POLL_FIRST_KEY();
+			orderedSet.REMOVE_FIRST_KEY();
 			polled++;
 		}
 		assertTrue("Map should be empty", orderedSet.isEmpty());
@@ -82,7 +82,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 		int polled = 0;
 		int expectedPolls = orderedSet.size();
 		while(polled < expectedPolls) {
-			orderedSet.POLL_LAST_KEY();
+			orderedSet.REMOVE_LAST_KEY();
 			polled++;
 		}
 		assertTrue("Map should be empty", orderedSet.isEmpty());
@@ -94,8 +94,8 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testEmptySetPollFirst() {
 		try {
-			orderedSet.POLL_FIRST_KEY();
-			fail("OrderedSet.POLL_FIRST_KEY should throw NoSuchElementException");
+			orderedSet.REMOVE_FIRST_KEY();
+			fail("OrderedSet.REMOVE_FIRST_KEY should throw NoSuchElementException");
 		} catch (NoSuchElementException e) {
 		}
 		expectUnchanged();
@@ -107,8 +107,8 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testEmptySetPollLast() {
 		try {
-			orderedSet.POLL_LAST_KEY();
-			fail("OrderedSet.POLL_LAST_KEY should throw NoSuchElementException");
+			orderedSet.REMOVE_LAST_KEY();
+			fail("OrderedSet.REMOVE_LAST_KEY should throw NoSuchElementException");
 		} catch (NoSuchElementException e) {
 		}
 		expectUnchanged();
@@ -119,8 +119,8 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testUnsupportedSetPollFirst() {
 		try {
-			orderedSet.POLL_FIRST_KEY();
-			fail("OrderedSet.POLL_FIRST_KEY should throw UnsupportedOperationException");
+			orderedSet.REMOVE_FIRST_KEY();
+			fail("OrderedSet.REMOVE_FIRST_KEY should throw UnsupportedOperationException");
 		} catch (UnsupportedOperationException e) {
 		}
 		expectUnchanged();
@@ -131,8 +131,8 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testUnsupportedSetPollLast() {
 		try {
-			orderedSet.POLL_LAST_KEY();
-			fail("OrderedSet.POLL_LAST_KEY should throw UnsupportedOperationException");
+			orderedSet.REMOVE_LAST_KEY();
+			fail("OrderedSet.REMOVE_LAST_KEY should throw UnsupportedOperationException");
 		} catch (UnsupportedOperationException e) {
 		}
 		expectUnchanged();
@@ -143,7 +143,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 	@CollectionSize.Require(ONE)
 #endignore
 	public void testSingletonSetPollFirst() {
-		assertEquals(a, orderedSet.POLL_FIRST_KEY());
+		assertEquals(a, orderedSet.REMOVE_FIRST_KEY());
 		assertTrue(orderedSet.isEmpty());
 	}
 	
@@ -152,7 +152,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 	@CollectionSize.Require(ONE)
 #endignore
 	public void testSingletonSetPollLast() {
-		assertEquals(a, orderedSet.POLL_LAST_KEY());
+		assertEquals(a, orderedSet.REMOVE_LAST_KEY());
 		assertTrue(orderedSet.isEmpty());
 	}
 	
@@ -161,7 +161,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 	@CollectionSize.Require(SEVERAL)
 #endignore
 	public void testPollFirst() {
-		assertEquals(a, orderedSet.POLL_FIRST_KEY());
+		assertEquals(a, orderedSet.REMOVE_FIRST_KEY());
 		assertEquals(values.subList(1, values.size()), HELPERS.copyToList(orderedSet));
 	}

@@ -170,7 +170,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 	@CollectionSize.Require(SEVERAL)
 #endignore
 	public void testPollLast() {
-		assertEquals(c, orderedSet.POLL_LAST_KEY());
+		assertEquals(c, orderedSet.REMOVE_LAST_KEY());
 		assertEquals(values.subList(0, values.size()-1), HELPERS.copyToList(orderedSet));
 	}
 	
@@ -179,7 +179,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testPollFirstUnsupported() {
 		try {
-			orderedSet.POLL_FIRST_KEY();
+			orderedSet.REMOVE_FIRST_KEY();
 			fail();
 		} catch (UnsupportedOperationException e) {
 		}
@@ -190,7 +190,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testPollLastUnsupported() {
 		try {
-			orderedSet.POLL_LAST_KEY();
+			orderedSet.REMOVE_LAST_KEY();
 			fail();
 		} catch (UnsupportedOperationException e) {
 		}
@@ -201,7 +201,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testEmptySetFirst() {
 		try {
-			orderedSet.FIRST_KEY();
+			orderedSet.GET_FIRST_KEY();
 			fail();
 		} catch (NoSuchElementException e) {
 		}
@@ -212,7 +212,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testEmptySetLast() {
 		try {
-			orderedSet.LAST_KEY();
+			orderedSet.GET_LAST_KEY();
 			fail();
 		} catch (NoSuchElementException e) {
 		}
@@ -222,27 +222,27 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 	@CollectionSize.Require(ONE)
 #endignore
 	public void testSingletonSetFirst() {
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 	}

 #ignore
 	@CollectionSize.Require(ONE)
 #endignore
 	public void testSingletonSetLast() {
-		assertEquals(a, orderedSet.LAST_KEY());
+		assertEquals(a, orderedSet.GET_LAST_KEY());
 	}

 #ignore
 	@CollectionSize.Require(SEVERAL)
 #endignore
 	public void testFirst() {
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 	}

 #ignore
 	@CollectionSize.Require(SEVERAL)
 #endignore
 	public void testLast() {
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 	}
 }
@@ -12,6 +12,9 @@ import com.google.common.collect.testing.features.CollectionSize;
 import com.google.common.collect.testing.features.SetFeature;
 import com.google.common.collect.testing.features.Feature;
 #if TYPE_OBJECT
+import com.google.common.collect.testing.testers.CollectionAddTester;
+import com.google.common.collect.testing.testers.CollectionAddAllTester;
+import com.google.common.collect.testing.testers.CollectionCreationTester;
 import com.google.common.collect.testing.features.CollectionFeature;
 #endif
 import junit.framework.Test;
@@ -122,6 +125,9 @@ public class SET_TESTS extends TestCase
 #ignore
 			.withFeatures(getSizes(size)).withFeatures(features);
 		if(nullValues) builder.withFeatures(CollectionFeature.ALLOWS_NULL_VALUES);
+		builder.suppressing(CollectionAddTester.getAddNullUnsupportedMethod(), CollectionAddTester.getAddNullSupportedMethod());
+		builder.suppressing(CollectionAddAllTester.getAddAllNullUnsupportedMethod());
+		builder.suppressing(CollectionCreationTester.getCreateWithNullUnsupportedMethod());
 #endignore
 		return builder.createTestSuite();
 	}
@@ -41,6 +41,8 @@ import speiger.src.collections.PACKAGE.maps.impl.misc.ARRAY_MAP;
 #if TYPE_OBJECT
 import speiger.src.collections.PACKAGE.maps.impl.misc.ENUM_MAP;
 import speiger.src.collections.PACKAGE.maps.impl.misc.LINKED_ENUM_MAP;
+import speiger.src.collections.PACKAGE.maps.impl.reference.REF_MAP;
+import speiger.src.collections.PACKAGE.maps.impl.reference.LINKED_REF_MAP;
 #endif
 import speiger.src.collections.PACKAGE.maps.impl.tree.AVL_TREE_MAP;
 import speiger.src.collections.PACKAGE.maps.impl.tree.RB_TREE_MAP;
@@ -104,6 +106,7 @@ public class MAP_TESTS extends TestCase
 #if TYPE_OBJECT
 		constructors.addTest(new TestSuite(MAP_CONSTRUCTOR_TESTS.EnumMap.class));
 		constructors.addTest(new TestSuite(MAP_CONSTRUCTOR_TESTS.LinkedEnumMap.class));
+		constructors.addTest(new TestSuite(MAP_CONSTRUCTOR_TESTS.RefMap.class));
 #endif
 		constructors.addTest(new TestSuite(MAP_CONSTRUCTOR_TESTS.CustomHashMap.class));
 		constructors.addTest(new TestSuite(MAP_CONSTRUCTOR_TESTS.LinkedCustomHashMap.class));
@@ -130,27 +133,29 @@ public class MAP_TESTS extends TestCase
 	}
 	
 	public static void suite(TestSuite suite) {
-		suite.addTest(mapSuite("HASH_MAP", HASH_MAP::new, getFeatures(), -1, true));
-		suite.addTest(orderedMapSuite("LINKED_HASH_MAP", LINKED_HASH_MAP::new, getFeatures(), -1));
-		suite.addTest(orderedMapSuite("IMMUTABLE_HASH_MAP", IMMUTABLE_HASH_MAP::new, getImmutableFeatures(), -1));
+		suite.addTest(mapSuite("HASH_MAP", HASH_MAP::new, getFeatures(), -1, true, true));
+		suite.addTest(orderedMapSuite("LINKED_HASH_MAP", LINKED_HASH_MAP::new, getFeatures(), -1, true));
+		suite.addTest(orderedMapSuite("IMMUTABLE_HASH_MAP", IMMUTABLE_HASH_MAP::new, getImmutableFeatures(), -1, true));
 #if TYPE_OBJECT
 		suite.addTest(enumMapSuite("ENUM_MAP", ENUM_MAP::new, getFeatures(), 5));
 		suite.addTest(enumOrderedMapSuite("LINKED_ENUM_MAP", (K, V) -> K.length <= 0 ? new LINKED_ENUM_MAP<>(AnEnum.class) : new LINKED_ENUM_MAP<>(K, V), getFeatures(), 5));
+		suite.addTest(mapSuite("REF_MAP", REF_MAP::new, getFeatures(), - 1, true, false));
+		suite.addTest(orderedMapSuite("LINKED_REF_MAP", LINKED_REF_MAP::new, getFeatures(), - 1, false));
 #endif
-		suite.addTest(mapSuite("CUSTOM_HASH_MAP", (K, V) -> new CUSTOM_HASH_MAPKV_BRACES(K, V, HashStrategy.INSTANCE), getFeatures(), -1, true));
-		suite.addTest(orderedMapSuite("LINKED_CUSTOM_HASH_MAP", (K, V) -> new LINKED_CUSTOM_HASH_MAPKV_BRACES(K, V, HashStrategy.INSTANCE), getFeatures(), -1));
-		suite.addTest(orderedMapSuite("ARRAY_MAP", ARRAY_MAP::new, getFeatures(), -1));
+		suite.addTest(mapSuite("CUSTOM_HASH_MAP", (K, V) -> new CUSTOM_HASH_MAPKV_BRACES(K, V, HashStrategy.INSTANCE), getFeatures(), -1, true, true));
+		suite.addTest(orderedMapSuite("LINKED_CUSTOM_HASH_MAP", (K, V) -> new LINKED_CUSTOM_HASH_MAPKV_BRACES(K, V, HashStrategy.INSTANCE), getFeatures(), -1, true));
+		suite.addTest(orderedMapSuite("ARRAY_MAP", ARRAY_MAP::new, getFeatures(), -1, true));
 		suite.addTest(concurrentMapSuite("CONCURRENT_HASH_MAP", CONCURRENT_HASH_MAP::new, getFeatures(), 2));
 		suite.addTest(concurrentMapSuite("CONCURRENT_HASH_MAP", CONCURRENT_HASH_MAP::new, getFeatures(), 3));
 		suite.addTest(navigableMapSuite("RB_TREE_MAP", RB_TREE_MAP::new, getFeatures(), -1));
 		suite.addTest(navigableMapSuite("AVL_TREE_MAP", AVL_TREE_MAP::new, getFeatures(), -1));
 		suite.addTest(navigableMapSuite("SynchronizedRB_TREE_MAP", (K, V) -> new RB_TREE_MAPKV_BRACES(K, V).synchronize(), getLimitedFeatures(), -1));
 		suite.addTest(navigableMapSuite("UnmodifiableRB_TREE_MAP", (K, V) -> new RB_TREE_MAPKV_BRACES(K, V).unmodifiable(), getLimitedImmutableFeatures(), -1));
-		suite.addTest(orderedMapSuite("SynchronizedORDERED_MAP", (K, V) -> new LINKED_HASH_MAPKV_BRACES(K, V).synchronize(), getFeatures(), -1));
-		suite.addTest(orderedMapSuite("UnmodifiableORDERED_MAP", (K, V) -> new LINKED_HASH_MAPKV_BRACES(K, V).unmodifiable(), getImmutableFeatures(), -1));
-		suite.addTest(mapSuite("EmptyMAP", (K, V) -> MAPS.empty(), getEmptyFeatures(), 0, false));
-		suite.addTest(mapSuite("SingletonMAP", (K, V) -> MAPS.singleton(K[0], V[0]), getEmptyFeatures(), 1, false));
-		suite.addTest(mapSuite("AbstractMap", SIMPLE_TEST_MAP::new, getTestFeatures(), -1, false));
+		suite.addTest(orderedMapSuite("SynchronizedORDERED_MAP", (K, V) -> new LINKED_HASH_MAPKV_BRACES(K, V).synchronize(), getFeatures(), -1, true));
+		suite.addTest(orderedMapSuite("UnmodifiableORDERED_MAP", (K, V) -> new LINKED_HASH_MAPKV_BRACES(K, V).unmodifiable(), getImmutableFeatures(), -1, true));
+		suite.addTest(mapSuite("EmptyMAP", (K, V) -> MAPS.empty(), getEmptyFeatures(), 0, false, true));
+		suite.addTest(mapSuite("SingletonMAP", (K, V) -> MAPS.singleton(K[0], V[0]), getEmptyFeatures(), 1, false, true));
+		suite.addTest(mapSuite("AbstractMap", SIMPLE_TEST_MAP::new, getTestFeatures(), -1, false, true));
 	}
 	
 #if TYPE_OBJECT
@@ -209,14 +214,14 @@ public class MAP_TESTS extends TestCase
 	
 #endif
 	
-	private static Test mapSuite(String name, BiFunction<KEY_STRING_TYPE[], VALUE_STRING_TYPE[], MAP KEY_VALUE_STRING_GENERIC_TYPE> factory, Collection<Feature<?>> features, int size, boolean sorted) {
+	private static Test mapSuite(String name, BiFunction<KEY_STRING_TYPE[], VALUE_STRING_TYPE[], MAP KEY_VALUE_STRING_GENERIC_TYPE> factory, Collection<Feature<?>> features, int size, boolean sorted, boolean allowNullKeys) {
 		SIMPLE_MAP_TEST_GENERATOR.Maps KEY_VALUE_STRING_GENERIC_TYPE generator = new SIMPLE_MAP_TEST_GENERATOR.Maps KEY_VALUE_STRING_GENERIC_TYPE(factory);
 		MAP_TEST_BUILDER KEY_VALUE_STRING_GENERIC_TYPE builder = MAP_TEST_BUILDER.using(generator);
 		builder.shouldBlockKeys(sorted);
 #if TYPE_OBJECT
 		generator.setKeys(createKeys());
 #ignore
-		builder.withFeatures(MapFeature.ALLOWS_NULL_KEYS);
+		if(allowNullKeys) builder.withFeatures(MapFeature.ALLOWS_NULL_KEYS);
 #endignore
 #endif
 #if VALUE_OBJECT
@@ -265,13 +270,13 @@ public class MAP_TESTS extends TestCase
 		return builder.named(name).createTestSuite();
 	}
 	
-	private static Test orderedMapSuite(String name, BiFunction<KEY_STRING_TYPE[], VALUE_STRING_TYPE[], ORDERED_MAP KEY_VALUE_STRING_GENERIC_TYPE> factory, Collection<Feature<?>> features, int size) {
+	private static Test orderedMapSuite(String name, BiFunction<KEY_STRING_TYPE[], VALUE_STRING_TYPE[], ORDERED_MAP KEY_VALUE_STRING_GENERIC_TYPE> factory, Collection<Feature<?>> features, int size, boolean allowNullKeys) {
 		SIMPLE_MAP_TEST_GENERATOR.OrderedMaps KEY_VALUE_STRING_GENERIC_TYPE generator = new SIMPLE_MAP_TEST_GENERATOR.OrderedMaps KEY_VALUE_STRING_GENERIC_TYPE(factory);
 		ORDERED_MAP_TEST_BUILDER KEY_VALUE_STRING_GENERIC_TYPE builder = ORDERED_MAP_TEST_BUILDER.using(generator);
 #if TYPE_OBJECT
 		generator.setKeys(createKeys());
 #ignore
-		builder.withFeatures(MapFeature.ALLOWS_NULL_KEYS);
+		if(allowNullKeys) builder.withFeatures(MapFeature.ALLOWS_NULL_KEYS);
 #endignore
 #endif
 #if VALUE_OBJECT
@@ -0,0 +1,5 @@
+package speiger.src.collections.utils;
+
+public interface Swapper {
+	public void swap(int fromIndex, int toIndex);
+}
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Speiger	21ccbee3b2	Disabled Google Tests that we don't have to deal.	2026-05-14 21:32:16 +02:00
Speiger	58a9eb38b4	Loads of additions. -Added: Indirect Sorters. -Added: ReferenceMaps -Fixed: A bunch of smaller bugs found due to tests	2026-05-14 19:21:38 +02:00
Speiger	2f1525ab57	Fixes and new updates. - Added: Collectors to lists/queues/sets - Fixed: Bugs in linked hash sets. - Fixed: Bugs in unit tests.	2026-05-14 02:51:38 +02:00
Speiger	9f46091282	Added Tests for Ordered Maps and more work on completing the implementation	2026-05-12 13:37:22 +02:00
Speiger	3d39d5526d	Breaking update - Added: Optionals for the missing JDK ones. - Removed: Default values for Reduce and FindFirst. Using Optionals instead.	2026-05-11 18:00:00 +02:00
Speiger	c6f656ee66	Switched to yearly activity	2026-05-11 00:36:08 +02:00
Speiger	f0139d1a22	Fixed Badge Generator	2026-05-11 00:34:48 +02:00
Speiger	58e20bb513	Fixed Enums	2026-05-11 00:10:44 +02:00
Speiger	502f22cea3	Removed java 25 support. Gradlew isn't supporting this yet.	2026-05-10 22:11:18 +02:00
Speiger	90e3b7110a	Updated Actions	2026-05-10 22:09:21 +02:00
Speiger	a26106cc89	Fixed a bunch of Iterator code and implemented Reverse Map/Set Tests	2026-05-10 22:00:55 +02:00
Speiger	d002f0094f	Updated Build Matrix to incude newer java versions and remove obsolete ones	2026-05-09 05:25:26 +02:00
Speiger	042460a338	Started Adding support for JDK21 SequencedCollections. Implementation is mostly finished. Just need to iron out bugs. But at this point i want to push activity.	2026-05-09 05:22:35 +02:00
Speiger	20927a97eb	Reworked Module Settings System Changelog: - Added: Dependency System that will resolve missing classes and enable them as needed. (This isn't perfect on some low level modules like Functions) - Added: Dependency Error system that will throw errors if a dependency is that is required is specifically disabled. - Added: Default setting for "undefined" entries. - Fixed: A few bugs that made the dependency system unnecessary difficult. - Updated: Documentation	2025-03-09 23:29:13 +01:00
Speiger	ebe75b0fea	Fixing a few things and testing more. Not useable atm.	2025-03-08 01:08:31 +01:00
Speiger	a6be24c59d	Start of a Advanced Dependency System. The idea behind this system is that you can select systems a lot easier. So if a custom system isn't required it can be disabled and all the subsystems that require it either get disabled too. it also allows you to set systems as: Only if they are required. Meaning if only a specific system is required its dependencies can still load.	2025-03-08 01:08:31 +01:00
Speiger	afdd27648e	Updated Changelog and Readme to include Maven Central	2024-04-11 19:11:07 +02:00
Speiger	7e475b5472	Fixed a few bugs in the maven central script	2024-03-30 05:12:57 +01:00
Speiger	e65fde736b	Fixed	2024-03-30 01:08:38 +01:00
Speiger	bf0b4172de	Added Maven central Badge	2024-03-30 01:07:46 +01:00
Speiger	961b47a58c	Fixed java8 compat	2024-03-30 01:02:42 +01:00
Speiger	330be87338	finalizing the maven central release.	2024-03-30 00:32:37 +01:00
Speiger	4b30ce12c9	Upgraded thread workers and disable GPG temporarly.	2024-03-29 22:35:44 +01:00
Speiger	0be7dba5d3	Fixed script bug	2024-03-29 22:26:34 +01:00
SpeigerandSpeiger	6eaa992f5f	Create SECURITY.md	2024-03-29 22:19:29 +01:00
Speiger	9b23d713ff	Started maven publish plugin.	2024-03-29 22:17:38 +01:00
Speiger	85d230c561	Fixed a auto generation bug where iterators wouldn't accept settings	2023-07-04 17:29:32 +02:00