*/
    static class TestSearcher extends RankFusionSearcher {
        @Override
        protected SearchResult search(String query, SearchRequestParams params, OptionalThing<FessUserBean> userBean) {
            return SearchResult.create().build();
        }
    }

    /**
     * Custom searcher implementation.
     */
    static class CustomSearcher extends RankFusionSearcher {
        @Override