throws Exception {
    ExecutorService executorService = newFixedThreadPool(numberOfThreads);
    try {
      CountDownLatch startLatch = new CountDownLatch(numberOfThreads);
      CountDownLatch doneLatch = new CountDownLatch(numberOfThreads);
      for (int i = numberOfThreads; i > 0; i--) {
        @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored

        assertTrue("Expected minimal sleep time with negative interval, got " + elapsed + "ms", elapsed < 50);
    }

    @Test
    public void test_update_callsLoad() throws InterruptedException {
        CountDownLatch latch = new CountDownLatch(1);
        configHelper.setLoadCallback(() -> {
            latch.countDown();
            return 1;
        });

        configHelper.update();

    ExecutorService service = newFixedThreadPool(4);
    ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
    try {
      queue.addListener(listener, service);

      CountDownLatch latch = new CountDownLatch(1);
      Multiset<Object> counters = ConcurrentHashMultiset.create();
      queue.enqueue(incrementingEvent(counters, listener, 1));
      queue.enqueue(incrementingEvent(counters, listener, 2));

    ExecutorService service = newFixedThreadPool(4);
    ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
    try {
      queue.addListener(listener, service);

      CountDownLatch latch = new CountDownLatch(1);
      Multiset<Object> counters = ConcurrentHashMultiset.create();
      queue.enqueue(incrementingEvent(counters, listener, 1));
      queue.enqueue(incrementingEvent(counters, listener, 2));

            .build(computingFunction);

    // seed the map, so its segment's count > 0
    cache.getUnchecked("a");
    shouldWait.set(true);

    CountDownLatch computationStarted = new CountDownLatch(1);
    CountDownLatch computationComplete = new CountDownLatch(1);
    new Thread(
            () -> {
              computationStarted.countDown();
              cache.getUnchecked("b");

            .build(computingFunction);

    // seed the map, so its segment's count > 0
    cache.getUnchecked("a");
    shouldWait.set(true);

    CountDownLatch computationStarted = new CountDownLatch(1);
    CountDownLatch computationComplete = new CountDownLatch(1);
    new Thread(
            () -> {
              computationStarted.countDown();
              cache.getUnchecked("b");

    CountDownLatch computeSignal = new CountDownLatch(1);
    // tells the main thread when computation is pending
    CountDownLatch secondSignal = new CountDownLatch(1);
    // tells the main thread when the second get has started
    CountDownLatch thirdSignal = new CountDownLatch(1);
    // tells the main thread when the third get has started
    CountDownLatch fourthSignal = new CountDownLatch(1);

            assertEquals("Test exception", e.getMessage());
        }
    }

    @Test
    public void test_processThreadDump_withCustomThread() throws InterruptedException {
        CountDownLatch latch = new CountDownLatch(1);
        AtomicInteger customThreadFound = new AtomicInteger(0);

        // Create a custom thread with recognizable name
        Thread customThread = new Thread(() -> {
            try {

      throws Exception {
    ExecutorService executorService = newFixedThreadPool(numberOfThreads);
    try {
      CountDownLatch startLatch = new CountDownLatch(numberOfThreads);
      CountDownLatch doneLatch = new CountDownLatch(numberOfThreads);
      for (int i = numberOfThreads; i > 0; i--) {
        @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored

    assertThat(e).hasCauseThat().hasMessageThat().isEqualTo("1");
  }

  private class ThreadedService extends AbstractService {
    final CountDownLatch hasConfirmedIsRunning = new CountDownLatch(1);

    /*
     * The main test thread tries to stop() the service shortly after
     * confirming that it is running. Meanwhile, the service itself is trying