*/
    public static final String HTTP_ADDRESS = "crawler.opensearch.http_address";

    /**
     * Target indices for OpenSearch.
     */
    public static final String TARGET_INDICES = "crawler.opensearch.target_indices";

    /**
     * Logger instance.
     */
    private static final Logger logger = LogManager.getLogger(FesenClient.class);

    /**
     * The OpenSearch client.
     */