protected function _family()
    {
        $arr = array();
        $int_code = $this->_unicode()->value;

        foreach (self::$arr_blocks as $b) {
            if ($int_code >= $b['start'] && $int_code <= $b['end']) {
                $arr = range($b['start'], $b['end']);

                foreach ($arr as $k => $v) {
                    $arr[$k] = new self(new N($v));
                }

                break;
            }
        }

        if (count($arr)) {
            return new A($arr);
        }

        throw new \Exception('Invalid character, it is unavailable in any unicode block.');
    }