Add method foreachAsync to Sink object

akka-docs/src/test/java/jdocs/stream/SinkRecipeDocTest.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2018 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package jdocs.stream;
+
+import akka.NotUsed;
+import akka.actor.ActorSystem;
+import akka.japi.function.Function;
+import akka.stream.ActorMaterializer;
+import akka.stream.Materializer;
+import akka.stream.javadsl.Source;
+import akka.stream.javadsl.Sink;
+import jdocs.AbstractJavaTest;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+
+public class SinkRecipeDocTest extends AbstractJavaTest {
+    static ActorSystem system;
+    static Materializer mat;
+
+    @BeforeClass
+    public static void setup() {
+        system = ActorSystem.create("SinkRecipeDocTest");
+        mat = ActorMaterializer.create(system);
+    }
+
+    @Test
+    public void foreachAsync() {
+        final Function<Integer, CompletionStage<Void>> asyncProcessing = param -> CompletableFuture.completedFuture(param).thenAccept(System.out::println);
+
+        //#forseachAsync-processing
+        //final Function<Integer, CompletionStage<Void>> asyncProcessing = _
+
+        final Source<Integer, NotUsed> numberSource = Source.range(1, 100);
+
+        numberSource
+            .runWith(Sink.foreachAsync(10, asyncProcessing), mat);
+        //#forseachAsync-processing
+    }
+}