int newRemaining = decrementRemainingAndGet();
    checkState(newRemaining >= 0, "Less than 0 remaining futures");
    if (newRemaining == 0) {
      processCompleted(futuresIfNeedToCollectAtCompletion);
    }
  }

  private void processCompleted(
      @Nullable ImmutableCollection<? extends Future<? extends InputT>>
          futuresIfNeedToCollectAtCompletion) {
    if (futuresIfNeedToCollectAtCompletion != null) {