*
   * Finalizer Thread runs instance of -> Finalizer.class loaded by -> Application class loader
   * which loaded -> ReferenceMap.class which has a static -> FinalizableReferenceQueue instance
   *
   * Even if no other references to classes from the application class loader remain, the Finalizer
   * thread keeps an indirect strong reference to the queue in ReferenceMap, which keeps the

        @DisplayName("Should maintain thread safety")
        void testThreadSafety() throws InterruptedException {
            int threadCount = 10;
            Thread[] threads = new Thread[threadCount];
            boolean[] success = new boolean[threadCount];

            for (int i = 0; i < threadCount; i++) {
                final int index = i;
                threads[i] = new Thread(() -> {
                    try {

    ClassLoader oldContextLoader = Thread.currentThread().getContextClassLoader();
    try {
      Thread.currentThread().setContextClassLoader(loader);
      URL url = Resources.getResource(tempFile.getName());
      String text = Resources.toString(url, UTF_8);
      assertThat(text).isEqualTo("rud a chur ar an méar fhada" + System.lineSeparator());
    } finally {
      Thread.currentThread().setContextClassLoader(oldContextLoader);

    assertFalse(future.isDone());
    assertFalse(future.isCancelled());

    CountDownLatch successLatch = new CountDownLatch(1);

    // Run cancellation in a separate thread as an extra thread-safety test.
    new Thread(
            () -> {
              assertThrows(CancellationException.class, future::get);
              successLatch.countDown();
            })
        .start();

        try (InputStream input = in; ByteArrayOutputStream out = new ByteArrayOutputStream()) {
            byte[] buf = new byte[8192];
            int read;
            while ((read = input.read(buf)) >= 0) {
                out.write(buf, 0, read);
            }
            return out.toString(StandardCharsets.UTF_8.name());
        }
    }

  }

  @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;
        default:

      return;
    }
    TimedWaiterThread thread = new TimedWaiterThread(new AbstractFuture<Object>() {}, 2, SECONDS);
    thread.start();
    thread.awaitWaiting();
    Thread.class.getMethod("suspend").invoke(thread);
    // Sleep for enough time to add 1500 milliseconds of overwait to the get() call.
    long toWaitMillis = 3500 - NANOSECONDS.toMillis(System.nanoTime() - thread.startTime);
    Thread.sleep(toWaitMillis);

                }
            });
            readThreads[i].start();
        }

        // Wait for all threads
        for (Thread thread : updateThreads) {
            thread.join(5000);
        }
        for (Thread thread : readThreads) {
            thread.join(5000);
        }

        // Verify final state
        assertEquals(100, entry.getChildren().size());

        // Poll for thread to process exceptions
        for (int i = 0; i < 20; i++) {
            if (!indexUpdater.isAlive() || indexUpdater.getState() == Thread.State.WAITING
                    || indexUpdater.getState() == Thread.State.TIMED_WAITING) {
                break;
            }
            Thread.sleep(100);
        }

        // Clean up the thread
        indexUpdater.setFinishCrawling(true);

        // Start a thread to set crawler running after a delay
        Thread thread = new Thread(() -> {
            try {
                Thread.sleep(100);
                helper.setCrawlerRunning(true);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        });
        thread.start();