// listener, and set this.futures to null.
      // This is not actually a problem, since the foreach only needs this.futures to be non-null
      // at the beginning of the loop.
      int i = 0;
      for (ListenableFuture<? extends InputT> future : futures) {
        int index = i++;
        future.addListener(
            () -> {
              try {
                if (future.isCancelled()) {

      // listener, and set this.futures to null.
      // This is not actually a problem, since the foreach only needs this.futures to be non-null
      // at the beginning of the loop.
      int i = 0;
      for (ListenableFuture<? extends InputT> future : futures) {
        int index = i++;
        future.addListener(
            () -> {
              try {
                if (future.isCancelled()) {

   *   <li>To retrieve a result from a {@code Future} that is already done, use {@link
   *       Futures#getDone Futures.getDone}.
   *   <li>To treat {@link InterruptedException} uniformly with other exceptions, use {@link
   *       Futures#getChecked(Future, Class, long, TimeUnit) Futures.getChecked}.
   *   <li>To get uninterruptibility and remove checked exceptions, use {@link
   *       Futures#getUnchecked}.
   * </ul>
   *

    private final ListenableFuture<@Nullable Void> future;
    private boolean called = false;

    private TestCallable(ListenableFuture<@Nullable Void> future) {
      this.future = future;
    }

    @Override
    public ListenableFuture<@Nullable Void> call() throws Exception {
      called = true;
      return future;
    }
  }

      List<Future<String>> futures = testExecutor.invokeAll(tasks);
      mock.assertLastMethodCalled("invokeAll");
      checkResults(futures);
    }
    {
      MockExecutor mock = new MockExecutor();
      TimeUnit unit = TimeUnit.SECONDS;
      long timeout = 5;
      TestExecutor testExecutor = new TestExecutor(mock);
      List<Future<String>> futures = testExecutor.invokeAll(tasks, timeout, unit);

      List<Future<String>> futures = testExecutor.invokeAll(tasks);
      mock.assertLastMethodCalled("invokeAll");
      checkResults(futures);
    }
    {
      MockExecutor mock = new MockExecutor();
      TimeUnit unit = TimeUnit.SECONDS;
      long timeout = 5;
      TestExecutor testExecutor = new TestExecutor(mock);
      List<Future<String>> futures = testExecutor.invokeAll(tasks, timeout, unit);

  let summary = "Allocate futures and promsies for tensorflow tensors";

  let description = [{
    Allocate futures and promsies for tensorflow tensors.

    $num_futures: The number of futures to be allocated.

    $promises: There are $num_futures promises. promises[i] shares the state with futures[i].
    $futures: There are $num_futures futures. futures[i] shares the state with promises[i].
  }];

  @CanIgnoreReturnValue
  @ParametricNullness
  static <V extends @Nullable Object, X extends Exception> V getChecked(
      Future<V> future, Class<X> exceptionClass) throws X {
    return getChecked(bestGetCheckedTypeValidator(), future, exceptionClass);
  }

  /** Implementation of {@link Futures#getChecked(Future, Class)}. */
  @CanIgnoreReturnValue
  @VisibleForTesting
  @ParametricNullness

   *   <li>To retrieve a result from a {@code Future} that is already done, use {@link
   *       Futures#getDone Futures.getDone}.
   *   <li>To treat {@link InterruptedException} uniformly with other exceptions, use {@link
   *       Futures#getChecked(Future, Class, long, TimeUnit) Futures.getChecked}.
   *   <li>To get uninterruptibility and remove checked exceptions, use {@link
   *       Futures#getUnchecked}.
   * </ul>
   *

    private final ListenableFuture<@Nullable Void> future;
    private boolean called = false;

    private TestCallable(ListenableFuture<@Nullable Void> future) {
      this.future = future;
    }

    @Override
    public ListenableFuture<@Nullable Void> call() throws Exception {
      called = true;
      return future;
    }
  }