() -> {
              enterLatch.countDown();
              new CountDownLatch(1).await(); // wait forever
              return immediateFuture(null);
            });
    assertFalse(task.isDone());
    Thread thread =
        new Thread(
            () -> {
              try {
                task.run();
              } finally {
                exitLatch.countDown();
              }
            },

            () -> {
              enterLatch.countDown();
              new CountDownLatch(1).await(); // wait forever
              return immediateFuture(null);
            });
    assertFalse(task.isDone());
    Thread thread =
        new Thread(
            () -> {
              try {
                task.run();
              } finally {
                exitLatch.countDown();
              }
            },

    @Override
    public void run() {
      assertTrue("Listener called before it was expected", expectCall);
      assertFalse("Listener called more than once", wasCalled());
      calledCountDown.countDown();
    }

    void expectCall() {
      assertFalse("expectCall is already true", expectCall);
      expectCall = true;
    }

    boolean wasCalled() {
      return calledCountDown.getCount() == 0;
    }

          @Override
          String runInterruptibly() throws Exception {
            BrokenChannel bc = new BrokenChannel();
            bc.doBegin();
            isInterruptibleRegistered.countDown();
            new CountDownLatch(1).await(); // the interrupt will wake us up
            return "impossible!";
          }

          @Override
          boolean isDone() {
            return false;
          }

          @Override
          String runInterruptibly() throws Exception {
            BrokenChannel bc = new BrokenChannel();
            bc.doBegin();
            isInterruptibleRegistered.countDown();
            new CountDownLatch(1).await(); // the interrupt will wake us up
            return "impossible!";
          }

          @Override
          boolean isDone() {
            return false;
          }

    @Override
    public void run() {
      assertTrue("Listener called before it was expected", expectCall);
      assertFalse("Listener called more than once", wasCalled());
      calledCountDown.countDown();
    }

    void expectCall() {
      assertFalse("expectCall is already true", expectCall);
      expectCall = true;
    }

    boolean wasCalled() {
      return calledCountDown.getCount() == 0;
    }

        cache.getUnchecked(getKey);
        getFinishedSignal.countDown();
      }
    }.start();
    new Thread() {
      @Override
      public void run() {
        cache.refresh(refreshKey);
        getFinishedSignal.countDown();
      }
    }.start();

    // let computation complete
    letGetFinishSignal.countDown();
    getFinishedSignal.await();
    checkNothingLogged();

    service.expectedShutdownState = Service.State.RUNNING;

    service.startAsync().awaitRunning();
    assertTrue(service.startUpCalled);
    assertEquals(Service.State.RUNNING, service.state());

    exitRun.countDown(); // the service will exit voluntarily
    executionThread.join();

    assertTrue(service.shutDownCalled);
    assertEquals(Service.State.TERMINATED, service.state());

    Runnable execute = list::execute;
    Thread thread1 = new Thread(execute);
    Thread thread2 = new Thread(execute);
    thread1.start();
    thread2.start();
    assertEquals(0, runCalled.get());
    okayToRun.countDown();
    thread1.join();
    thread2.join();
    assertEquals(1, runCalled.get());
  }

  public void testAddAfterRun() throws Exception {
    // Run the previous test
    testRunOnPopulatedList();

        } finally {
          closedLatch.countDown()
        }
      }
    }.buffer()

  override val sink: BufferedSink =
    object : ForwardingSink(delegate.sink) {
      private var closed = false

      override fun close() {
        if (closed) return
        try {
          super.close()
        } finally {
          closedLatch.countDown()
        }
      }
    }.buffer()