final String value = getSearchEngineHttpSslCertificateAuthorities();
        if (value != null) {
            return value;
        }
        return get("elasticsearch.http.ssl.certificate_authorities");
    }

    String getSearchEngineUsername();

    default String getFesenUsername() {
        final String value = getSearchEngineUsername();
        if (value != null) {

search_engine.type=default
# The URL of the search engine HTTP endpoint.
search_engine.http.url=http://localhost:9201
# Path to SSL certificate authorities for secure HTTP connections.
search_engine.http.ssl.certificate_authorities=
# Username for authenticating to the search engine.
search_engine.username=
# Password for authenticating to the search engine.
search_engine.password=
# Interval (ms) for heartbeat checks to the search engine.