public static function hasKanji($str, $extended = false)
    {
        if ($extended) {
            return preg_match(Helper::PREG_PATTERN_KANJI_EXTENDED, $str, $matches) > 0;
        } else {
            return preg_match(Helper::PREG_PATTERN_KANJI, $str, $matches) > 0;
        }
    }