}
            return normalizeQueryLanguages(langs);
        }

        if (requestLangs != null && requestLangs.length != 0) {
            return normalizeQueryLanguages(requestLangs);
        }

        if (locales == null) {
            return StringUtil.EMPTY_STRINGS;
        }

        return normalizeQueryLanguages(Collections.list(locales).stream().map(locale -> {

        };

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