public function encodeHex($str)
    {
        if (!ctype_xdigit((string)$str)) {
            return '';
        }

        $numbers = trim(chunk_split($str, 12, ' '));
        $numbers = explode(' ', $numbers);

        foreach ($numbers as $i => $number) {
            $numbers[$i] = hexdec('1' . $number);
        }

        return call_user_func_array([$this, 'encode'], $numbers);
    }