// TODO(cpovirk): Test forwarding more extensively.
  }

  public void testAddCallback() {
    FluentFuture<String> f = FluentFuture.from(immediateFuture("a"));
    final boolean[] called = new boolean[1];
    f.addCallback(
        new FutureCallback<String>() {
          @Override
          public void onSuccess(String result) {
            called[0] = true;
          }

          @Override

    // TODO(cpovirk): Test forwarding more extensively.
  }

  public void testAddCallback() {
    FluentFuture<String> f = FluentFuture.from(immediateFuture("a"));
    final boolean[] called = new boolean[1];
    f.addCallback(
        new FutureCallback<String>() {
          @Override
          public void onSuccess(String result) {
            called[0] = true;
          }

          @Override

   * @since 10.0
   */
  public static <V extends @Nullable Object> void addCallback(
      final ListenableFuture<V> future,
      final FutureCallback<? super V> callback,
      Executor executor) {
    Preconditions.checkNotNull(callback);
    future.addListener(new CallbackListener<V>(future, callback), executor);
  }

  /** See {@link #addCallback(ListenableFuture, FutureCallback, Executor)} for behavioral notes. */

   *   <li>If an exception propagates out of a {@code Runnable}, it is not necessarily seen by any
   *       {@code UncaughtExceptionHandler} for the thread. For example, if the callback passed to
   *       {@link Futures#addCallback} throws an exception, that exception will be typically be
   *       logged by the {@link ListenableFuture} implementation, even if the thread is configured

          ListenableFuture<C> future, final Executor closingExecutor) {
    checkNotNull(closingExecutor);
    final ClosingFuture<C> closingFuture = new ClosingFuture<>(nonCancellationPropagating(future));
    Futures.addCallback(
        future,
        new FutureCallback<@Nullable Closeable>() {
          @Override
          public void onSuccess(@CheckForNull Closeable result) {