waiter1.start();
    waiter1.awaitWaiting();

    WaiterThread waiter2 = new WaiterThread(future);
    waiter2.start();
    waiter2.awaitWaiting();
    // The waiter queue should be waiter2->waiter1

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

    waiter1.start();
    waiter1.awaitWaiting();

    WaiterThread waiter2 = new WaiterThread(future);
    waiter2.start();
    waiter2.awaitWaiting();
    // The waiter queue should be waiter2->waiter1

    // This should wake up waiter1 and cause the waiter1 node to be removed.
    waiter1.interrupt();

    waiter1.join();
    waiter2.awaitWaiting(); // should still be blocked

        return new OldAbstractFutureFacade<T>();
      }
    };

    abstract <T> Facade<T> newFacade();
  }

  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  static void awaitWaiting(Thread t) {
    while (true) {
      Thread.State state = t.getState();
      switch (state) {
        case RUNNABLE:
        case BLOCKED:
          Thread.yield();
          break;
        case WAITING:

        return new OldAbstractFutureFacade<T>();
      }
    };

    abstract <T> Facade<T> newFacade();
  }

  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  static void awaitWaiting(Thread t) {
    while (true) {
      Thread.State state = t.getState();
      switch (state) {
        case RUNNABLE:
        case BLOCKED:
          Thread.yield();
          break;
        case WAITING:

    // Check that we wait long enough anyway (presumably as long as MAX_VALUE nanos):
    TimedWaiterThread waiter = new TimedWaiterThread(future, Long.MAX_VALUE, SECONDS);
    waiter.start();
    waiter.awaitWaiting();

    future.set(1);
    waiter.join();
  }

  @J2ktIncompatible // TODO(b/324550390): Enable
  public void testSetNull() throws Exception {
    future.set(null);

    // Check that we wait long enough anyway (presumably as long as MAX_VALUE nanos):
    TimedWaiterThread waiter = new TimedWaiterThread(future, Long.MAX_VALUE, SECONDS);
    waiter.start();
    waiter.awaitWaiting();

    future.set(1);
    waiter.join();
  }

  @J2ktIncompatible // TODO(b/324550390): Enable
  public void testSetNull() throws Exception {
    future.set(null);