* <p>The default implementation of this method in {@code AbstractFuture} does nothing. This is
   * intended for very lightweight cleanup work, for example, timing statistics or clearing fields.
   * If your task does anything heavier consider, just using a listener with an executor.
   *
   * @since 20.0
   */
  @ForOverride
  protected void afterDone() {}

    state = State.CANCELLED;
    notifyAndClearListeners();

    if (delegate != null) {
      // TODO(lukes): consider adding the StackOverflowError protection from the server version
      delegate.cancel(mayInterruptIfRunning);
    }

    return true;
  }

  protected void interruptTask() {}

  @Override
  public boolean isCancelled() {