String expected = "MyCallableString";
    Callable<String> callable = () -> expected;

    AsyncCallable<String> asyncCallable =
        Callables.asAsyncCallable(callable, newDirectExecutorService());

    ListenableFuture<String> future = asyncCallable.call();
    assertThat(future.get()).isEqualTo(expected);
  }

  @J2ktIncompatible
  @GwtIncompatible

    String expected = "MyCallableString";
    Callable<String> callable = () -> expected;

    AsyncCallable<String> asyncCallable =
        Callables.asAsyncCallable(callable, newDirectExecutorService());

    ListenableFuture<String> future = asyncCallable.call();
    assertThat(future.get()).isEqualTo(expected);
  }

  @J2ktIncompatible
  @GwtIncompatible

    @SuppressWarnings("AnonymousToLambda") // We want an instance that can be GCed.
    AsyncCallable<Long> combiner =
        new AsyncCallable<Long>() {
          @Override
          public ListenableFuture<Long> call() {
            return SettableFuture.create();
          }
        };
    WeakReference<AsyncCallable<Long>> combinerRef = new WeakReference<>(combiner);

    ListenableFuture<Long> unused =

    @SuppressWarnings("AnonymousToLambda") // We want an instance that can be GCed.
    AsyncCallable<Long> combiner =
        new AsyncCallable<Long>() {
          @Override
          public ListenableFuture<Long> call() {
            return SettableFuture.create();
          }
        };
    WeakReference<AsyncCallable<Long>> combinerRef = new WeakReference<>(combiner);

    ListenableFuture<Long> unused =

   *
   * @throws RejectedExecutionException if the task cannot be scheduled for execution
   * @since 23.0
   */
  public static <O extends @Nullable Object> ListenableFuture<O> submitAsync(
      AsyncCallable<O> callable, Executor executor) {
    TrustedListenableFutureTask<O> task = TrustedListenableFutureTask.create(callable);
    executor.execute(task);
    return task;
  }

  /**

    }

    void stop() {
      stopLatch.countDown();
    }

    boolean isRunning() {
      return running;
    }
  }

  private static final class TestCallable implements AsyncCallable<@Nullable Void> {

    private final ListenableFuture<@Nullable Void> future;
    private boolean called = false;

    private TestCallable(ListenableFuture<@Nullable Void> future) {
      this.future = future;

    }

    void stop() {
      stopLatch.countDown();
    }

    boolean isRunning() {
      return running;
    }
  }

  private static final class TestCallable implements AsyncCallable<@Nullable Void> {

    private final ListenableFuture<@Nullable Void> future;
    private boolean called = false;

    private TestCallable(ListenableFuture<@Nullable Void> future) {
      this.future = future;

     */
    public final <V extends @Nullable Object> ClosingFuture<V> callAsync(
        AsyncCombiningCallable<V> combiningCallable, Executor executor) {
      AsyncCallable<V> asyncCallable =
          new AsyncCallable<V>() {
            @Override
            public ListenableFuture<V> call() throws Exception {
              return new Peeker(inputs).callAsync(combiningCallable, closeables);
            }