* @return An optional containing the query languages array, or empty if not available.
     */
    protected OptionalThing<String[]> getQueryLanguages() {
        return LaRequestUtil.getOptionalRequest()
                .map(request -> ComponentUtil.getFessConfig()
                        .getQueryLanguages(request.getLocales(), (String[]) request.getAttribute(Constants.REQUEST_LANGUAGES)));
    }

    /**

            }
            return mapping.get(s.split("[\\-_]")[0]);
        }).filter(StringUtil::isNotBlank).distinct().toArray(n -> new String[n]));
    }

    default String[] getQueryLanguages(final Enumeration<Locale> locales, final String[] requestLangs) {
        // requestLangs > default > browser
        if (StringUtil.isNotBlank(getQueryDefaultLanguages())) {