protected static Map<String, Map<String, FieldAnalyzerMapping>> fieldAnalyzerMappingMap = new ConcurrentHashMap<>();

    /** Supported languages. */
    protected static final String[] SUPPORTED_LANGUAGES = { "ar", "bg", "bn", "ca", "cs", "da", "de", "el", "en", "es", "et", "fa", "fi",
            "fr", "gu", "he", "hi", "hr", "hu", "id", "it", "ja", "ko", "lt", "lv", "mk", "ml", "nl", "no", "pa", "pl", "pt", "ro", "ru",

    /** The key of the configuration. e.g. _query */
    String QUERY_GSA_DEFAULT_PREFERENCE = "query.gsa.default.preference";

    /** The key of the configuration. e.g. ar=ar<br>
     * bg=bg<br>
     * bn=bn<br>
     * ca=ca<br>
     * ckb-iq=ckb-iq<br>
     * ckb_IQ=ckb-iq<br>
     * cs=cs<br>
     * da=da<br>
     * de=de<br>
     * el=el<br>
     * en=en<br>