* It implements rank fusion techniques to combine results from different search engines
 * and provides a unified search interface.
 */
public class RankFusionProcessor implements AutoCloseable {

    private static final Logger logger = LogManager.getLogger(RankFusionProcessor.class);

    /** Array of rank fusion searchers available for processing search requests */
    protected RankFusionSearcher[] searchers = new RankFusionSearcher[1];

            final OptionalThing<FessUserBean> userBean) {
        final RankFusionProcessor rankFusionProcessor = ComponentUtil.getRankFusionProcessor();
        final List<Map<String, Object>> documentItems = rankFusionProcessor.search(query, params, userBean);
        if (documentItems instanceof final QueryResponseList queryResponseList) {