protected function parseStringRule(string $rules): array
    {
        $parameters = [];

        // The format for specifying validation rules and parameters follows an
        // easy {rule}:{parameters} formatting convention. For instance the
        // rule "Min:3" states that the value may only be three letters.
        if (\mb_strpos($rules, ':') !== false) {
            [$rules, $parameter] = \explode(':', $rules, 2);

            $parameters = $this->parseParameters($rules, $parameter);
        }

        return [\trim($rules), $parameters];
    }