private function rangeError($type, $high, $low = null)
    {
        $range   = null === $low ? sprintf('greater than %d', $high) : sprintf('out of range %d to %d', $low, $high);
        $message = sprintf('[Range Error] Error: %s %s in value "%s"', $type, $range, $this->input);

        return new RangeException($message);
    }