diff --git a/.classpath b/.classpath
index 6190f20..1e326ef 100644
--- a/.classpath
+++ b/.classpath
@@ -2,6 +2,7 @@
 <classpath>
 	<classpathentry kind="src" output="target/test-classes" path="src/test/java">
 		<attributes>
+			<attribute name="test" value="true"/>
 			<attribute name="optional" value="true"/>
 			<attribute name="maven.pomderived" value="true"/>
 		</attributes>
@@ -17,7 +18,7 @@
 			<attribute name="maven.pomderived" value="true"/>
 		</attributes>
 	</classpathentry>
-	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JDK 12">
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-12">
 		<attributes>
 			<attribute name="module" value="true"/>
 			<attribute name="maven.pomderived" value="true"/>
@@ -28,5 +29,11 @@
 			<attribute name="maven.pomderived" value="true"/>
 		</attributes>
 	</classpathentry>
+	<classpathentry excluding="**" kind="src" output="target/test-classes" path="src/test/resources">
+		<attributes>
+			<attribute name="test" value="true"/>
+			<attribute name="maven.pomderived" value="true"/>
+		</attributes>
+	</classpathentry>
 	<classpathentry kind="output" path="target/classes"/>
 </classpath>
diff --git a/.settings/org.eclipse.jdt.core.prefs b/.settings/org.eclipse.jdt.core.prefs
index 8b5c4dc..c447060 100644
--- a/.settings/org.eclipse.jdt.core.prefs
+++ b/.settings/org.eclipse.jdt.core.prefs
@@ -1,9 +1,9 @@
 eclipse.preferences.version=1
 org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
 org.eclipse.jdt.core.compiler.codegen.methodParameters=do not generate
-org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=12
 org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
-org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.compliance=12
 org.eclipse.jdt.core.compiler.debug.lineNumber=generate
 org.eclipse.jdt.core.compiler.debug.localVariable=generate
 org.eclipse.jdt.core.compiler.debug.sourceFile=generate
@@ -11,6 +11,6 @@ org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
 org.eclipse.jdt.core.compiler.problem.enablePreviewFeatures=disabled
 org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
 org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning
-org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=ignore
-org.eclipse.jdt.core.compiler.release=disabled
-org.eclipse.jdt.core.compiler.source=1.8
+org.eclipse.jdt.core.compiler.problem.reportPreviewFeatures=warning
+org.eclipse.jdt.core.compiler.release=enabled
+org.eclipse.jdt.core.compiler.source=12
diff --git a/README.md b/README.md
index 6fe64b1..52c85b4 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-[![Maven Central](https://img.shields.io/maven-central/v/net.tascalate/net.tascalate.concurrent.svg)](https://search.maven.org/artifact/net.tascalate/net.tascalate.concurrent/0.9.6/jar) [![GitHub release](https://img.shields.io/github/release/vsilaev/tascalate-concurrent.svg)](https://github.com/vsilaev/tascalate-concurrent/releases/tag/0.9.6) [![license](https://img.shields.io/github/license/vsilaev/tascalate-concurrent.svg)](http://www.apache.org/licenses/LICENSE-2.0.txt)
+[![Maven Central](https://img.shields.io/maven-central/v/net.tascalate/net.tascalate.concurrent.svg)](https://search.maven.org/artifact/net.tascalate/net.tascalate.concurrent/0.9.7/jar) [![GitHub release](https://img.shields.io/github/release/vsilaev/tascalate-concurrent.svg)](https://github.com/vsilaev/tascalate-concurrent/releases/tag/0.9.7) [![license](https://img.shields.io/github/license/vsilaev/tascalate-concurrent.svg)](http://www.apache.org/licenses/LICENSE-2.0.txt)
 # tascalate-concurrent
 The library provides an implementation of the [CompletionStage](https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CompletionStage.html) interface and related classes these are designed to support long-running blocking tasks (typically, I/O bound). This functionality augments the sole Java 8 built-in implementation, [CompletableFuture](https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CompletableFuture.html), that is primarily supports computational tasks. Also, the library helps with numerous asynchronous programing challenges like handling timeouts, retry/poll functionality, orchestrating results of multiple concurrent computations and similar.
 
@@ -12,7 +12,7 @@ New name:
 <dependency>
     <groupId>net.tascalate</groupId>
     <artifactId>net.tascalate.concurrent</artifactId>
-    <version>0.9.6</version> <!-- Any version above 0.8.0, the latest one is recommended -->
+    <version>0.9.7</version> <!-- Any version above 0.8.0, the latest one is recommended -->
 </dependency>
 ```
 Old Name
@@ -38,7 +38,7 @@ To use a library you have to add a single Maven dependency
 <dependency>
     <groupId>net.tascalate</groupId>
     <artifactId>net.tascalate.concurrent</artifactId>
-    <version>0.9.6</version>
+    <version>0.9.7</version>
 </dependency>
 ```
 # What is inside?
diff --git a/pom.xml b/pom.xml
index 531ca76..6d54bf6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 	 
 	<groupId>net.tascalate</groupId>
 	<artifactId>net.tascalate.concurrent</artifactId>
-	<version>0.9.6</version>
+	<version>0.9.7</version>
 	<packaging>jar</packaging>  
 
 	<name>Tascalate Concurrent</name>
diff --git a/src/main/java/net/tascalate/concurrent/PromiseOperations.java b/src/main/java/net/tascalate/concurrent/PromiseOperations.java
index cc6f405..4fea0c5 100644
--- a/src/main/java/net/tascalate/concurrent/PromiseOperations.java
+++ b/src/main/java/net/tascalate/concurrent/PromiseOperations.java
@@ -94,9 +94,9 @@ public static <T, F extends Promise<T>> Function<F, F> peek(Consumer<? super F>
         return p -> unwrap(Promises.tryComposeEx(p.dependent(PromiseOrigin.ALL), fn));
     }
     
-    public static <T, A, R> Function<Promise<Iterable<T>>, Promise<R>> 
+    public static <S, T, A, R> Function<Promise<Iterable<S>>, Promise<R>> 
         partitionedItems(int batchSize, 
-                         Function<? super T, CompletionStage<? extends T>> spawner,
+                         Function<? super S, CompletionStage<? extends T>> spawner,
                          Collector<T, A, R> downstream) {
         
         return p -> p.dependent()
@@ -105,9 +105,9 @@ public static <T, F extends Promise<T>> Function<F, F> peek(Consumer<? super F>
                      .unwrap();
     }
     
-    public static <T, A, R> Function<Promise<Iterable<T>>, Promise<R>> 
+    public static <S, T, A, R> Function<Promise<Iterable<S>>, Promise<R>> 
         partitionedItems(int batchSize, 
-                         Function<? super T, CompletionStage<? extends T>> spawner, 
+                         Function<? super S, CompletionStage<? extends T>> spawner, 
                          Collector<T, A, R> downstream,
                          Executor downstreamExecutor) {
         
@@ -117,9 +117,9 @@ public static <T, F extends Promise<T>> Function<F, F> peek(Consumer<? super F>
                      .unwrap();
     }
     
-    public static <T, A, R> Function<Promise<Stream<T>>, Promise<R>> 
+    public static <S, T, A, R> Function<Promise<Stream<S>>, Promise<R>> 
         partitionedStream(int batchSize, 
-                          Function<? super T, CompletionStage<? extends T>> spawner, 
+                          Function<? super S, CompletionStage<? extends T>> spawner, 
                           Collector<T, A, R> downstream) {
         
          return p -> p.dependent()
@@ -128,9 +128,9 @@ public static <T, F extends Promise<T>> Function<F, F> peek(Consumer<? super F>
                       .unwrap();
      }
     
-    public static <T, A, R> Function<Promise<Stream<T>>, Promise<R>> 
+    public static <S, T, A, R> Function<Promise<Stream<S>>, Promise<R>> 
         partitionedStream(int batchSize, 
-                          Function<? super T, CompletionStage<? extends T>> spawner, 
+                          Function<? super S, CompletionStage<? extends T>> spawner, 
                           Collector<T, A, R> downstream,
                           Executor downstreamExecutor) {
         
diff --git a/src/main/java/net/tascalate/concurrent/Promises.java b/src/main/java/net/tascalate/concurrent/Promises.java
index ba64034..7d46459 100644
--- a/src/main/java/net/tascalate/concurrent/Promises.java
+++ b/src/main/java/net/tascalate/concurrent/Promises.java
@@ -253,41 +253,41 @@ public static <T, R extends AsyncCloseable> Promise<T> tryComposeEx(Promise<R> p
                });
     }
     
-    public static <T, A, R> Promise<R> partitioned(Iterable<? extends T> values, 
-                                                   int batchSize, 
-                                                   Function<? super T, CompletionStage<? extends T>> spawner, 
-                                                   Collector<T, A, R> downstream) {
+    public static <S, T, A, R> Promise<R> partitioned(Iterable<? extends S> values, 
+                                                      int batchSize, 
+                                                      Function<? super S, CompletionStage<? extends T>> spawner, 
+                                                      Collector<T, A, R> downstream) {
         return partitioned1(values.iterator(), null, batchSize, spawner, downstream);
     }
     
-    public static <T, A, R> Promise<R> partitioned(Iterable<? extends T> values, 
-                                                   int batchSize, 
-                                                   Function<? super T, CompletionStage<? extends T>> spawner, 
-                                                   Collector<T, A, R> downstream,
-                                                   Executor downstreamExecutor) {
+    public static <S, T, A, R> Promise<R> partitioned(Iterable<? extends S> values, 
+                                                      int batchSize, 
+                                                      Function<? super S, CompletionStage<? extends T>> spawner, 
+                                                      Collector<T, A, R> downstream,
+                                                      Executor downstreamExecutor) {
         return partitioned2(values.iterator(), null, batchSize, spawner, downstream, downstreamExecutor);
     }
     
-    public static <T, A, R> Promise<R> partitioned(Stream<? extends T> values, 
-                                                   int batchSize, 
-                                                   Function<? super T, CompletionStage<? extends T>> spawner, 
-                                                   Collector<T, A, R> downstream) {
+    public static <S, T, A, R> Promise<R> partitioned(Stream<? extends S> values, 
+                                                      int batchSize, 
+                                                      Function<? super S, CompletionStage<? extends T>> spawner, 
+                                                      Collector<T, A, R> downstream) {
         return partitioned1(values.iterator(), values, batchSize, spawner, downstream);
     }
     
-    public static <T, A, R> Promise<R> partitioned(Stream<? extends T> values, 
-                                                   int batchSize, 
-                                                   Function<? super T, CompletionStage<? extends T>> spawner, 
-                                                   Collector<T, A, R> downstream,
-                                                   Executor downstreamExecutor) {
+    public static <S, T, A, R> Promise<R> partitioned(Stream<? extends S> values, 
+                                                      int batchSize, 
+                                                      Function<? super S, CompletionStage<? extends T>> spawner, 
+                                                      Collector<T, A, R> downstream,
+                                                      Executor downstreamExecutor) {
         return partitioned2(values.iterator(), values, batchSize, spawner, downstream, downstreamExecutor);
     }
     
-    private static <T, A, R> Promise<R> partitioned1(Iterator<? extends T> values, 
-                                                     Object source,
-                                                     int batchSize, 
-                                                     Function<? super T, CompletionStage<? extends T>> spawner, 
-                                                     Collector<T, A, R> downstream) {
+    private static <S, T, A, R> Promise<R> partitioned1(Iterator<? extends S> values, 
+                                                        Object source,
+                                                        int batchSize, 
+                                                        Function<? super S, CompletionStage<? extends T>> spawner, 
+                                                        Collector<T, A, R> downstream) {
         return
             parallelStep1(values, batchSize, spawner, downstream)
             .dependent()
@@ -296,12 +296,12 @@ private static <T, A, R> Promise<R> partitioned1(Iterator<? extends T> values,
             .unwrap();
     }
 
-    private static <T, A, R> Promise<R> partitioned2(Iterator<? extends T> values, 
-                                                     Object source,
-                                                     int batchSize, 
-                                                     Function<? super T, CompletionStage<? extends T>> spawner, 
-                                                     Collector<T, A, R> downstream,
-                                                     Executor downstreamExecutor) {
+    private static <S, T, A, R> Promise<R> partitioned2(Iterator<? extends S> values, 
+                                                        Object source,
+                                                        int batchSize, 
+                                                        Function<? super S, CompletionStage<? extends T>> spawner, 
+                                                        Collector<T, A, R> downstream,
+                                                        Executor downstreamExecutor) {
         return 
             parallelStep2(values, batchSize, spawner, downstream, downstreamExecutor)
             .dependent()
@@ -310,13 +310,13 @@ private static <T, A, R> Promise<R> partitioned2(Iterator<? extends T> values,
             .unwrap();
     }
     
-    private static <T, A, R> Promise<IndexedStep<A>> parallelStep1(
-        Iterator<? extends T> values, int batchSize,
-        Function<? super T, CompletionStage<? extends T>> spawner,                                                        
+    private static <S, T, A, R> Promise<IndexedStep<A>> parallelStep1(
+        Iterator<? extends S> values, int batchSize,
+        Function<? super S, CompletionStage<? extends T>> spawner,                                                        
         Collector<T, A, R> downstream) {
 
         return loop(new IndexedStep<>(), step -> step.initial() || values.hasNext(), step -> {
-            List<T> valuesBatch = drainBatch(values, batchSize);
+            List<S> valuesBatch = drainBatch(values, batchSize);
             if (valuesBatch.isEmpty()) {
                 // Over
                 return Promises.success(step.initial() ? step.next(downstream.supplier().get()) : step);
@@ -336,14 +336,14 @@ private static <T, A, R> Promise<IndexedStep<A>> parallelStep1(
         });
     }
 
-    private static <T, A, R> Promise<IndexedStep<A>> parallelStep2(
-        Iterator<? extends T> values, int batchSize,
-        Function<? super T, CompletionStage<? extends T>> spawner,                                                        
+    private static <S, T, A, R> Promise<IndexedStep<A>> parallelStep2(
+        Iterator<? extends S> values, int batchSize,
+        Function<? super S, CompletionStage<? extends T>> spawner,                                                        
         Collector<T, A, R> downstream,
         Executor downstreamExecutor) {
 
         return loop(new IndexedStep<>(), step -> step.initial() || values.hasNext(), step -> {
-            List<T> valuesBatch = drainBatch(values, batchSize);
+            List<S> valuesBatch = drainBatch(values, batchSize);
             if (valuesBatch.isEmpty()) {
                 // Over
                 return step.initial() ?