assertEquals(0L, indexUpdater.getDocumentSize());
    }

    // Test setUncaughtExceptionHandler
    public void test_setUncaughtExceptionHandler() {
        final AtomicBoolean handlerCalled = new AtomicBoolean(false);
        final Thread.UncaughtExceptionHandler handler = (t, e) -> handlerCalled.set(true);

        indexUpdater.setUncaughtExceptionHandler(handler);
        assertSame(handler, indexUpdater.getUncaughtExceptionHandler());

            try {
              cacheRef.get().getUnchecked(3);
            } finally {
              doneSignal.countDown();
            }
          }
        };
    thread.setUncaughtExceptionHandler(
        new UncaughtExceptionHandler() {
          @Override
          public void uncaughtException(Thread t, Throwable e) {}
        });
    thread.start();

      new Executor() {
        @Override
        public void execute(Runnable command) {
          executionThread = new Thread(command);
          executionThread.setUncaughtExceptionHandler(
              new UncaughtExceptionHandler() {
                @Override
                public void uncaughtException(Thread thread, Throwable e) {
                  thrownByExecutionThread = e;
                }

     *
     * @param eh the uncaught exception handler to set
     */
    @Override
    public void setUncaughtExceptionHandler(final UncaughtExceptionHandler eh) {
        super.setUncaughtExceptionHandler(eh);
    }

    /**
     * Sets the default uncaught exception handler for all threads.
     *
     * @param eh the default uncaught exception handler to set

    List<Thread> threads = new ArrayList<>(numThreads);
    List<Throwable> exceptions = new ArrayList<>(numThreads);
    for (int i = 0; i < numThreads; i++) {
      Thread thread = new Thread(task);
      thread.setUncaughtExceptionHandler(
          new UncaughtExceptionHandler() {
            @Override
            public void uncaughtException(Thread t, Throwable e) {
              exceptions.add(e);
            }
          });

    List<Thread> threads = new ArrayList<>(numThreads);
    List<Throwable> exceptions = new ArrayList<>(numThreads);
    for (int i = 0; i < numThreads; i++) {
      Thread thread = new Thread(task);
      thread.setUncaughtExceptionHandler(
          new UncaughtExceptionHandler() {
            @Override
            public void uncaughtException(Thread t, Throwable e) {
              exceptions.add(e);
            }
          });