*
   * @param consumer a callback whose method will be called (using {@code executor}) when this
   *     operation is done
   */
  public void finishToValueAndCloser(
      ValueAndCloserConsumer<? super V> consumer, Executor executor) {
    try {
      state.finishToValueAndCloser(consumer, executor);
    } finally {
      reachabilityFence(this);
    }
  }