*/
  @J2ktIncompatible
  @GwtIncompatible // java.time.Duration
  @IgnoreJRERequirement // Users will use this only if they're already using Duration.
  public static void addDelayedShutdownHook(ExecutorService service, Duration terminationTimeout) {
    addDelayedShutdownHook(service, toNanosSaturated(terminationTimeout), NANOSECONDS);
  }

  /**
   * Add a shutdown hook to wait for thread completion in the given {@link ExecutorService service}.

  public void testAddDelayedShutdownHook_success() throws InterruptedException {
    TestApplication application = new TestApplication();
    ExecutorService service = mock(ExecutorService.class);
    application.addDelayedShutdownHook(service, 2, SECONDS);
    verify(service, never()).shutdown();
    application.shutdown();
    InOrder shutdownFirst = inOrder(service);
    shutdownFirst.verify(service).shutdown();

  public void testAddDelayedShutdownHook_success() throws InterruptedException {
    TestApplication application = new TestApplication();
    ExecutorService service = mock(ExecutorService.class);
    application.addDelayedShutdownHook(service, 2, SECONDS);
    verify(service, never()).shutdown();
    application.shutdown();
    InOrder shutdownFirst = inOrder(service);
    shutdownFirst.verify(service).shutdown();