assertTrue(CrawlerStatus.INITIALIZING.compareTo(CrawlerStatus.DONE) < 0);
        assertTrue(CrawlerStatus.RUNNING.compareTo(CrawlerStatus.DONE) < 0);

        // Reverse comparisons
        assertTrue(CrawlerStatus.RUNNING.compareTo(CrawlerStatus.INITIALIZING) > 0);
        assertTrue(CrawlerStatus.DONE.compareTo(CrawlerStatus.INITIALIZING) > 0);

 *
 * Map<String, Object> document;
 * while ((document = reader.read()) != null) {
 *     // Process the document
 *     System.out.println(document);
 * }
 *
 * reader.close(); // Close the reader to release resources
 * }
 * </pre>
 */
public class ESSourceReader implements DocumentReader {
    private static final Logger logger = LogManager.getLogger(ESSourceReader.class);

    /** Queue of documents. */

 * ftpClient.init(); // Initialize with configured parameters
 * ResponseData responseData = ftpClient.doGet("ftp://example.com/path/to/file.txt");
 * // Process the responseData
 * ftpClient.close(); // Close and release resources
 * }
 * </pre>
 *
 * @author shinsuke
 */
public class FtpClient extends AbstractCrawlerClient {

    /** Logger instance for this class */