HM\BackUpWordPress\Requirement_Language::test PHP Method

    public static function test()
    {
        // Since 4.0
        $language = get_option('WPLANG');
        if ($language) {
            return $language;
        }
        if (defined('WPLANG') && WPLANG) {
            return WPLANG;
        }
        return 'en_US';
    }