}

    public void test_normalizeQueryLanguages() {
        FessProp.propMap.clear();
        FessConfig fessConfig = new FessConfig.SimpleImpl() {
            @Override
            public String getQueryLanguageMapping() {
                return "ja=ja\nzh_cn=zh-cn\nzh_TW=zh-tw\nzh=zh-cn";
            }
        };

        assertArrays(new String[] {}, fessConfig.normalizeQueryLanguages(new String[] {}));

    String getQueryDefaultLanguages();

    String getQueryLanguageMapping();

    default Map<String, String> getQueryLanguageMappingMap() {
        @SuppressWarnings("unchecked")
        Map<String, String> params = (Map<String, String>) propMap.get(QUERY_LANGUAGE_MAPPING);
        if (params == null) {
            params = stream(getQueryLanguageMapping().split("\n")).get(stream -> stream.filter(StringUtil::isNotBlank).map(v -> {

     * zh-tw=zh-tw<br>
     * zh_TW=zh-tw<br>
     * zh=zh<br>
     *  <br>
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getQueryLanguageMapping();

    /**
     * Get the value for the key 'query.boost.title'. <br>
     * The value is, e.g. 0.5 <br>
     * comment: boost