*   <li>Polling (retrieving and removing) a URL from the queue.</li>
 *   <li>Saving the session (currently a no-op).</li>
 *   <li>Checking if a URL has already been visited.</li>
 *   <li>Generating URL queues from a previous session's access results.</li>
 * </ul>
 *
 * <p>
 * The class uses synchronization to ensure thread safety when accessing and modifying the URL queue.

     * @return The crawler client.
     */
    protected CrawlerClient getClient(final String url) {
        return clientFactory.getClient(url);
    }

    /**
     * Checks if the content has been updated since the last crawl.
     * @param client The crawler client.
     * @param urlQueue The URL queue entry.
     * @return true if content is updated, false otherwise.
     */

    /**
     * Helper for managing content length validation and limits.
     */
    @Resource
    protected ContentLengthHelper contentLengthHelper;

    /**
     * Flag indicating whether the client has been initialized.
     */
    protected volatile boolean isInit = false;

    /**
     * The MinIO client instance for interacting with object storage.
     */
    protected MinioClient minioClient;