final UrlQueue<?> urlQueue = new UrlQueueImpl<>();
        urlQueue.setUrl("http://example.com/");
        urlQueue.setDepth(1);

        when(urlFilter.match(anyString())).thenReturn(true);

        // Use reflection to access protected method
        final java.lang.reflect.Method method = CrawlerThread.class.getDeclaredMethod("isValid", UrlQueue.class);
        method.setAccessible(true);

        assertTrue("Index creation should be acknowledged", response.isAcknowledged());

        final Suggester suggester = Suggester.builder().build(client, "test");

        // Use reflection to access private method
        final Method method = Suggester.class.getDeclaredMethod("getIndicesForAlias", String.class);
        method.setAccessible(true);

        URLConnection conn = handler.openConnection(url);

        assertTrue(conn instanceof Handler.GcsURLConnection);
        Handler.GcsURLConnection gcsConn = (Handler.GcsURLConnection) conn;

        // Use reflection to access private fields for testing
        assertEquals("mybucket", getField(gcsConn, "bucketName"));
        assertEquals("path/to/object.txt", getField(gcsConn, "objectName"));
    }

    /**

        assertTrue(conn instanceof Handler.StorageURLConnection);
        Handler.StorageURLConnection storageConn = (Handler.StorageURLConnection) conn;

        // Use reflection to access private fields for testing
        assertEquals("mybucket", getField(storageConn, "bucketName"));
        assertEquals("path/to/object.txt", getField(storageConn, "objectName"));
    }

    /**

└── fess-crawler-opensearch/   # OpenSearch backend
```

### Key Design Patterns

**Factory**: `CrawlerClientFactory`, `ExtractorFactory` - protocol/format-specific component selection
**Strategy**: `CrawlerClient`, `Extractor`, `Transformer` - pluggable implementations
**Builder**: `RequestDataBuilder`, `ExtractorBuilder` - fluent construction

 * This class implements AutoCloseable to properly handle resource cleanup.
 *
 * <p>The factory maintains a map of regular expression patterns to crawler clients,
 * allowing for URL-based client selection. Clients can be added with specific patterns
 * and optionally at specific positions in the processing order.</p>
 *
 * <p>This factory is typically initialized through dependency injection and can be

 * <li>Document expiration handling</li>
 * <li>Child URL extraction and queueing</li>
 * <li>Integration with Fess configuration and permission systems</li>
 * <li>Client selection based on URL patterns</li>
 * </ul>
 *
 * @see CrawlerThread
 * @see org.codelibs.fess.crawler.client.CrawlerClient
 */
public class FessCrawlerThread extends CrawlerThread {

    /**

     *
     * This method prioritizes explicit language parameters over browser locale settings
     * and handles special cases like "all languages" selection.
     *
     * @param request The HTTP servlet request
     * @param params The search request parameters
     * @return Array of normalized language codes
     */