protected static function matchRule($postalCode, $rule)
    {
        if (substr($rule, 0, 1) == '/' && substr($rule, -1, 1) == '/') {
            $match = preg_match($rule, $postalCode);
        } else {
            $match = in_array($postalCode, self::buildList($rule));
        }

        return $match;
    }