}

    private FutureCombiner<@Nullable Object> futureCombiner() {
      return allMustSucceed
          ? Futures.whenAllSucceed(inputFutures())
          : Futures.whenAllComplete(inputFutures());
    }

    private ImmutableList<FluentFuture<?>> inputFutures() {
      return FluentIterable.from(inputs)
          .<FluentFuture<?>>transform(future -> future.future)
          .toList();
    }
  }

  @Override
  protected ListenableFuture<String> buildChainingFuture(ListenableFuture<Integer> inputFuture) {
    outputFuture = SettableFuture.create();
    funcIsWaitingLatch = new CountDownLatch(1);
    funcCompletionLatch = new CountDownLatch(1);
    return transformAsync(inputFuture, new ChainingFunction(), directExecutor());
  }

  @Override
  protected String getSuccessfulResult() {

  @Override
  protected ListenableFuture<String> buildChainingFuture(ListenableFuture<Integer> inputFuture) {
    outputFuture = SettableFuture.create();
    funcIsWaitingLatch = new CountDownLatch(1);
    funcCompletionLatch = new CountDownLatch(1);
    return transformAsync(inputFuture, new ChainingFunction(), directExecutor());
  }

  @Override
  protected String getSuccessfulResult() {