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"));
    }

    /**

    }

    @Test
    public void test_ProtectedConstructor() throws Exception {
        // ## Test that protected constructor can be accessed via reflection ##

        // ## Act ##
        final Constructor<Curl> constructor = Curl.class.getDeclaredConstructor();
        constructor.setAccessible(true);
        final Curl instance = constructor.newInstance();

        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"));
    }

    /**

        }
        return id.substring(0, idPrefixLength) + MessageDigestUtil.digest("SHA-256", id.substring(idPrefixLength));
    }

    /**
     * Extracts the URL from the target object using reflection.
     *
     * @param target The target object.
     * @return The URL string, or null if not found.
     */
    private String getUrl(final Object target) {

└── 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

   ```bash
   # Run the main class in your IDE
   org.codelibs.fess.FessBoot
   ```

2. **Access the Admin UI:**
   ```
   http://localhost:8080/admin/
   ```

3. **Test language selection:**
   - Check if your language appears in the language dropdown
   - Force your language by adding URL parameter: `?browser_lang=[locale]`
   - Example: `http://localhost:8080/admin/?browser_lang=sv`

 * 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 {

    /**