*/
  final boolean casListeners(@Nullable Listener expect, Listener update) {
    return ATOMIC_HELPER.casListeners(this, expect, update);
  }

  /**
   * Performs a {@linkplain java.lang.invoke.VarHandle#getAndSet get-and-set} operation on {@link
   * #listenersField}.
   */
  final @Nullable Listener gasListeners(Listener update) {
    return ATOMIC_HELPER.gasListeners(this, update);
  }

  /**

    implements ListenableFuture<V> {
  final boolean casListeners(@Nullable Listener expect, Listener update) {
    if (listeners == expect) {
      listeners = update;
      return true;
    }
    return false;
  }

  final @Nullable Listener gasListeners(Listener update) {
    Listener old = listeners;
    listeners = update;
    return old;
  }

        .filter(
            m ->
                m.getName().equals("getDoneValue")
                    || m.getName().equals("casValue")
                    || m.getName().equals("casListeners")
                    || m.getName().equals("gasListeners"))
        .forEach(ignoredMembers::add);
  }

  /**
   * Sets a default value that can be used for any parameter of type {@code type}. Returns this
   * object.
   */

        .filter(
            m ->
                m.getName().equals("getDoneValue")
                    || m.getName().equals("casValue")
                    || m.getName().equals("casListeners")
                    || m.getName().equals("gasListeners"))
        .forEach(ignoredMembers::add);
  }

  /**
   * Sets a default value that can be used for any parameter of type {@code type}. Returns this
   * object.
   */

      Listener oldHead = listeners();
      if (oldHead != Listener.TOMBSTONE) {
        Listener newNode = new Listener(listener, executor);
        do {
          newNode.next = oldHead;
          if (casListeners(oldHead, newNode)) {
            return;
          }
          oldHead = listeners(); // re-read
        } while (oldHead != Listener.TOMBSTONE);
      }
    }

    private final ExecutionList executionList = new ExecutionList();

    // This allows us to only start up a thread waiting on the delegate future when the first
    // listener is added.
    private final AtomicBoolean hasListeners = new AtomicBoolean(false);

    // The delegate future.
    private final Future<V> delegate;

    ListenableFutureAdapter(Future<V> delegate) {
      this(delegate, defaultAdapterExecutor);
    }