private final @Nullable ListenableFuture<? extends T>[] inputFutures;
    private volatile int delegateIndex = 0;

    private InCompletionOrderState(ListenableFuture<? extends T>[] inputFutures) {
      this.inputFutures = inputFutures;
      incompleteOutputCount = new AtomicInteger(inputFutures.length);
    }

    private void recordOutputCancellation(boolean interruptIfRunning) {

    }

    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.state.future)
          .toList();
    }