/**
     * Priority for crawler threads.
     */
    protected int threadPriority = Thread.NORM_PRIORITY;

    /**
     * Reference to the parent thread that started the crawler.
     */
    protected Thread parentThread;

    /**
     * The thread group for crawler threads.
     */
    protected ThreadGroup crawlerThreadGroup;

    /**

            }
          }
        });
    awaitUninterruptibly(enteredLatch);
  }

  @CanIgnoreReturnValue
  static Thread startThread(Runnable runnable) {
    Thread thread = new Thread(runnable);
    thread.setDaemon(true);
    thread.start();
    return thread;
  }

  /**
   * Generates a test case verifying that calling any enterXxx, tryEnterXxx, or waitForXxx method

                    }
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                } finally {
                    endLatch.countDown();
                }
            }
        });

        Thread thread2 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {

      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);

            }

            seen = true;

            tg = aTgList;
            Thread[] ts = new Thread[tg.activeCount()];
            tg.enumerate(ts);

            for (Thread active : ts) {
                String name = active.getName();
                boolean daemon = active.isDaemon();
                assertTrue(daemon, name + " is no daemon Thread.");
            }
        }

        Thread[] threads = new Thread[threadNum];
        ESSourceReader reader = new ESSourceReader(client, settings, indexName);
        reader.setScrollSize(100);
        for (int i = 0; i < threadNum; i++) {
            threads[i] = new Thread(() -> {
                Map<String, Object> source;
                while ((source = reader.read()) != null) {

        }

        // Read partial content
        try (InputStream in = file.getInputStream()) {
            byte[] buffer = new byte[10];
            int bytesRead = in.read(buffer);
            assertEquals(10, bytesRead, "Should read requested bytes");
            assertEquals("0123456789", new String(buffer, 0, bytesRead, "UTF-8"));

            // Read next chunk
            bytesRead = in.read(buffer);

  public void testRenaming() throws Exception {
    String oldName = Thread.currentThread().getName();
    Supplier<String> newName = Suppliers.ofInstance("MyCrazyThreadName");
    Callable<@Nullable Void> callable =
        new Callable<@Nullable Void>() {
          @Override
          public @Nullable Void call() throws Exception {
            assertEquals(Thread.currentThread().getName(), newName.get());
            return null;

    assertTrue(Thread.holdsLock(mutex));
    return super.add(o);
  }

  @Override
  public boolean addAll(Collection<? extends E> c) {
    assertTrue(Thread.holdsLock(mutex));
    return super.addAll(c);
  }

  @Override
  public void clear() {
    assertTrue(Thread.holdsLock(mutex));
    super.clear();
  }

  @Override
  public boolean contains(@Nullable Object o) {
    assertTrue(Thread.holdsLock(mutex));

    assertTrue(Thread.holdsLock(mutex));
    return super.add(o);
  }

  @Override
  public boolean addAll(Collection<? extends E> c) {
    assertTrue(Thread.holdsLock(mutex));
    return super.addAll(c);
  }

  @Override
  public void clear() {
    assertTrue(Thread.holdsLock(mutex));
    super.clear();
  }

  @Override
  public boolean contains(@Nullable Object o) {
    assertTrue(Thread.holdsLock(mutex));