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 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) {

   */
  @CheckForNull @LazyInit ListenableFuture<? extends I> inputFuture;
  @CheckForNull @LazyInit F function;

  AbstractTransformFuture(ListenableFuture<? extends I> inputFuture, F function) {
    this.inputFuture = checkNotNull(inputFuture);
    this.function = checkNotNull(function);
  }

  @Override

   */
  @CheckForNull @LazyInit ListenableFuture<? extends V> inputFuture;
  @CheckForNull @LazyInit Class<X> exceptionType;
  @CheckForNull @LazyInit F fallback;

  AbstractCatchingFuture(
      ListenableFuture<? extends V> inputFuture, Class<X> exceptionType, F fallback) {
    this.inputFuture = checkNotNull(inputFuture);
    this.exceptionType = checkNotNull(exceptionType);

    @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = delegateRef;
    @RetainedLocalRef ScheduledFuture<?> localTimer = timer;
    if (localInputFuture != null) {
      String message = "inputFuture=[" + localInputFuture + "]";
      if (localTimer != null) {
        long delay = localTimer.getDelay(MILLISECONDS);
        // Negative delays look confusing in an error message
        if (delay > 0) {