return output;
  }

  /*
   * In certain circumstances, this field might theoretically not be visible to an afterDone() call
   * triggered by cancel(). For details, see the comments on the fields of TimeoutFuture.
   */
  @CheckForNull @LazyInit ListenableFuture<? extends I> inputFuture;
  @CheckForNull @LazyInit F function;

  AbstractTransformFuture(ListenableFuture<? extends I> inputFuture, F function) {

   */
  /*
   * In certain circumstances, this field might theoretically not be visible to an afterDone() call
   * triggered by cancel(). For details, see the comments on the fields of TimeoutFuture.
   */
  @CheckForNull @LazyInit
  private ImmutableCollection<? extends ListenableFuture<? extends InputT>> futures;

  private final boolean allMustSucceed;
  private final boolean collectsValues;