return value;
        }
        return get("elasticsearch.http.ssl.certificate_authorities");
    }

    String getSearchEngineUsername();

    default String getFesenUsername() {
        final String value = getSearchEngineUsername();
        if (value != null) {
            return value;
        }
        return get("elasticsearch.username");
    }

     * comment: Username for authenticating to the search engine.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getSearchEngineUsername();

    /**
     * Get the value for the key 'search_engine.username' as {@link Integer}. <br>
     * The value is, e.g.  <br>
     * comment: Username for authenticating to the search engine.