queue.addListener(listener, directExecutor());

    Multiset<Object> counters = ConcurrentHashMultiset.create();
    queue.enqueue(incrementingEvent(counters, listener, 1));
    queue.enqueue(incrementingEvent(counters, listener, 2));
    queue.enqueue(incrementingEvent(counters, listener, 3));
    queue.enqueue(incrementingEvent(counters, listener, 4));
    assertEquals(0, counters.size());
    queue.dispatch();

    queue.addListener(listener, directExecutor());

    Multiset<Object> counters = ConcurrentHashMultiset.create();
    queue.enqueue(incrementingEvent(counters, listener, 1));
    queue.enqueue(incrementingEvent(counters, listener, 2));
    queue.enqueue(incrementingEvent(counters, listener, 3));
    queue.enqueue(incrementingEvent(counters, listener, 4));
    assertEquals(0, counters.size());
    queue.dispatch();

     * and the counter returned by {@link #totalProblemsReported()} are not equal (latter is bigger than former).
     *
     * @return true if the problem collector has overflowed and some problems were not preserved
     */
    boolean problemsOverflow();

    /**
     * Reports a problem: always maintains the counters, but whether problem is preserved in memory, depends on

    public String createdTime;

    /** Version number for optimistic locking. */
    public String versionNo;

    /**
     * Clears all pagination state and filter parameters.
     * Resets pagination counters to default values and clears all filter fields.
     */
    public void clear() {
        allRecordCount = 0;
        allPageCount = 0;
        existPrePage = false;
        existNextPage = false;

    public String createdTime;

    /** Search parameter: version number */
    public String versionNo;

    /**
     * Clears all pagination data and search parameters.
     * Resets counters, flags, and search form fields to their default values.
     */
    public void clear() {
        allRecordCount = 0;
        allPageCount = 0;
        existPrePage = false;
        existNextPage = false;

        logger.resetStatistics();

        Map<EventType, Long> statsAfter = logger.getStatistics();
        // After reset, all counters should be 0
        for (Long count : statsAfter.values()) {
            assertEquals(Long.valueOf(0), count, "All statistics should be 0 after reset");
        }
    }

    @Test

        long currentWindow = System.currentTimeMillis() / rateLimitWindow;
        String windowKey = key + "_" + currentWindow;

        AtomicLong counter = rateLimitCounters.computeIfAbsent(windowKey, k -> new AtomicLong(0));
        long currentCount = counter.incrementAndGet();

        // Clean up old windows periodically
        if (currentCount == 1) {
            cleanupOldRateLimitCounters(currentWindow);
        }

   * exception is thrown, this exception is used as the result of the output {@code Future}.
   *
   * <p>Usage example:
   *
   * {@snippet :
   * // Falling back to a zero counter in case an exception happens when processing the RPC to fetch
   * // counters.
   * ListenableFuture<Integer> faultTolerantFuture =
   *     fetchCounters().catching(FetchException.class, x -> 0, directExecutor());
   * }
   *

    for (int i = 0; i < SIZE; i++) {
      aa.set(i, (double) COUNTDOWN);
    }
    Counter c1 = new Counter(aa);
    Counter c2 = new Counter(aa);
    Thread t1 = newStartedThread(c1);
    Thread t2 = newStartedThread(c2);
    awaitTermination(t1);
    awaitTermination(t2);
    assertEquals(SIZE * COUNTDOWN, c1.counts + c2.counts);
  }

  /** a deserialized serialized array holds same values */

    private CrawlerPooledObjectFactory<TestComponent> factory;
    private StandardCrawlerContainer container;

    @Override
    protected void setUp() throws Exception {
        super.setUp();

        // Reset counters before each test
        TestComponent.resetCounter();
        SingletonTestComponent.resetInstanceCount();

        // Initialize container with test components