public function accessOverride()
    {
        if (strpos($this->scheme, 'http') === 0) {
            switch (floor($this->code / 100) * 100) {
                case 300:
                case 400:
                    return self::DIRECTIVE_ALLOW;
                case 500:
                    return self::DIRECTIVE_DISALLOW;
            }
        }
        return false;
    }