verify(!(f instanceof FluentFuture));
    assertThat(FluentFuture.from(f).get()).isEqualTo("a");
    // 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