function ruleBetween($min, $max, $error_message = null) {
        if (!is_numeric($min)) {
            throw new \Exception('Incorrect parameter MIN in rule between');
        }
        if (!is_numeric($max)) {
            throw new \Exception('Incorrect parameter MAX in rule between');
        }

        return $this->_rule('between:' . $min . ',' . $max, $error_message);
    }