volatile @Nullable Waiter waitersField;

  /** Non-volatile write of the thread to the {@link Waiter#thread} field. */
  private static void putThread(Waiter waiter, Thread newValue) {
    ATOMIC_HELPER.putThread(waiter, newValue);
  }

  /** Non-volatile write of the waiter to the {@link Waiter#next} field. */
  private static void putNext(Waiter waiter, @Nullable Waiter newValue) {

  final TestCloseable closeable2 = new TestCloseable("closeable2");
  final TestCloseable closeable3 = new TestCloseable("closeable3");
  final TestCloseable closeable4 = new TestCloseable("closeable4");

  final Waiter waiter = new Waiter();
  final CountDownLatch futureCancelled = new CountDownLatch(1);
  final Exception exception = new Exception();
  final Closeable mockCloseable = mock(Closeable.class);

  @Override

                    } catch (InterruptedException e) {
                        // Ignore
                    }
                }
            });

            waiter.start();
            Thread.sleep(50); // Give waiter time to start

            response.received();

            assertTrue(latch.await(500, TimeUnit.MILLISECONDS));
            assertTrue(response.isReceived());
        }

  // TODO: Test blocking to re-enter monitor after being signaled.
  // TODO: Test interrupts with both interruptible and uninterruptible monitor.
  // TODO: Test multiple waiters: If guard is still satisfied, signal next waiter.
  // TODO: Test multiple waiters: If guard is no longer satisfied, do not signal next waiter.

  final TestCloseable closeable2 = new TestCloseable("closeable2");
  final TestCloseable closeable3 = new TestCloseable("closeable3");
  final TestCloseable closeable4 = new TestCloseable("closeable4");

  final Waiter waiter = new Waiter();
  final CountDownLatch futureCancelled = new CountDownLatch(1);
  final Exception exception = new Exception();
  final Closeable mockCloseable = mock(Closeable.class);

  @Override

    if (waiter.isAlive()) {
      waiter.interrupt();
      fail("awaitTermination failed to trigger after shutdown()");
    }
  }

  /** Wait for the given thread to reach the {@link State#TIMED_WAITING} thread state. */
  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  void awaitTimedWaiting(Thread thread) {
    while (true) {
      switch (thread.getState()) {

  // TODO: Test blocking to re-enter monitor after being signaled.
  // TODO: Test interrupts with both interruptible and uninterruptible monitor.
  // TODO: Test multiple waiters: If guard is still satisfied, signal next waiter.
  // TODO: Test multiple waiters: If guard is no longer satisfied, do not signal next waiter.

    if (waiter.isAlive()) {
      waiter.interrupt();
      fail("awaitTermination failed to trigger after shutdown()");
    }
  }

  /** Wait for the given thread to reach the {@link State#TIMED_WAITING} thread state. */
  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  void awaitTimedWaiting(Thread thread) {
    while (true) {
      switch (thread.getState()) {

    WaiterThread waiter1 = new WaiterThread(future);
    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();

    NoOpService service = new NoOpService();
    Thread waiter =
        new Thread() {
          @Override
          public void run() {
            service.awaitTerminated();
          }
        };
    waiter.start();
    service.startAsync().awaitRunning();
    assertEquals(State.RUNNING, service.state());
    service.stopAsync();