}
            }
        }
        return OptionalEntity.empty();
    }

    /**
     * Processes the search log queue.
     *
     * @param queue The search log queue.
     */
    protected void processSearchLogQueue(final Queue<SearchLog> queue) {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final String value = fessConfig.getPurgeByBots();
        String[] botNames;

        return URL_QUEUE_THREAD_LOCAL.get();
    }

    /**
     * Sets the URL queue for the current thread. If the provided URL queue is null,
     * the URL queue for the current thread is removed.
     *
     * @param urlQueue the URL queue to be set for the current thread, or null to remove the URL queue
     */
    public static void setUrlQueue(final UrlQueue<?> urlQueue) {
        if (urlQueue == null) {

     */
    protected String charsetName = CoreLibConstants.UTF_8;

    /**
     * The queue of ciphers for encryption.
     */
    protected Queue<Cipher> encryptoQueue = new ConcurrentLinkedQueue<>();

    /**
     * The queue of ciphers for decryption.
     */
    protected Queue<Cipher> decryptoQueue = new ConcurrentLinkedQueue<>();

    /**
     * Encrypts the given data.
     *

    }

    /**
     * Adds a URL to the crawling queue.
     * @param url The URL to add.
     */
    public void addUrl(final String url) {
        try {
            urlQueueService.add(crawlerContext.sessionId, url);
            if (logger.isDebugEnabled()) {
                logger.debug("Added URL to queue: url={}, sessionId={}", url, crawlerContext.sessionId);
            }

    /**
     * Maximum size of the thumbnail generation task queue.
     */
    protected int thumbnailTaskQueueSize = 10000;

    /**
     * Number of tasks to process in bulk operations.
     */
    protected int thumbnailTaskBulkSize = 100;

    /**
     * Timeout in milliseconds for thumbnail task queue operations.
     */
    protected long thumbnailTaskQueueTimeout = 10 * 1000L;

            }
        }
        return true;
    }

    /**
     * Stores child URLs from the given set into the crawling queue for future processing.
     * This method filters out blank URLs and increments the depth for child URLs.
     *
     * @param urlQueue the parent URL queue item
     * @param childUrlSet the set of child URLs to be queued for crawling
     */

        crawlerThread.setCrawlerContext(crawlerContext);

        when(crawlerContainer.available()).thenReturn(true);
    }

    /**
     * Test isValid method with a valid URL queue.
     */
    public void test_isValid_validUrlQueue() throws Exception {
        final UrlQueue<?> urlQueue = new UrlQueueImpl<>();
        urlQueue.setUrl("http://example.com/");
        urlQueue.setDepth(1);

    /**
     * The FTP client configuration.
     */
    protected FTPClientConfig ftpClientConfig;

    /**
     * The queue of FTPClient instances.
     */
    protected final Queue<FTPClient> ftpClientQueue = new ConcurrentLinkedQueue<>();

    /**
     * The active external host.
     */
    protected String activeExternalHost;

    /**

# Number of primary shards for crawler queue index.
index.document.crawler.queue.number_of_shards=10
# Number of primary shards for crawler data index.
index.document.crawler.data.number_of_shards=10
# Number of primary shards for crawler filter index.
index.document.crawler.filter.number_of_shards=10
# Number of replicas for crawler queue index.
index.document.crawler.queue.number_of_replicas=1

        final long elapsed = (System.nanoTime() - start) / 1000000;

        assertTrue("file:// URLs should not be delayed", elapsed < 50);
    }

    /**
     * Test that null URL queue is handled gracefully
     */
    public void test_nullUrlQueue() {
        final HostIntervalController controller = new HostIntervalController();
        controller.delayMillisBeforeProcessing = 1000L;