Overload HttpExecution.fromThread with ExecutionContextExecutor param

(cherry picked from commit 68854f2)

core/play/src/main/java/play/libs/concurrent/HttpExecution.java

@@ -28,6 +28,18 @@ public static ExecutionContextExecutor fromThread(ExecutionContext delegate) {
     return HttpExecutionContext.fromThread(delegate);
   }
 
+  /**
+   * An ExecutionContext that executes work on the given ExecutionContext. The current thread's
+   * context ClassLoader is captured when this method is called and preserved for all executed
+   * tasks.
+   *
+   * @param delegate the delegate execution context.
+   * @return the execution context wrapped in an {@link play.libs.concurrent.HttpExecutionContext}.
+   */
+  public static ExecutionContextExecutor fromThread(ExecutionContextExecutor delegate) {
+    return HttpExecutionContext.fromThread(delegate);
+  }
+
   /**
    * An ExecutionContext that executes work on the given ExecutionContext. The current thread's
    * context ClassLoader is captured when this method is called and preserved for all executed

documentation/manual/working/javaGuide/main/async/code/javaguide/async/controllers/Application.java

@@ -28,7 +28,7 @@ public Application(MyExecutionContext myExecutionContext) {
 
   public CompletionStage<Result> index() {
     // Wrap an existing thread pool, using the context from the current thread
-    Executor myEc = HttpExecution.fromThread((Executor) myExecutionContext);
+    Executor myEc = HttpExecution.fromThread(myExecutionContext);
     return supplyAsync(() -> intensiveComputation(), myEc)
         .thenApplyAsync(i -> ok("Got result: " + i), myEc);
   }