public function unauthenticated(Request $request, Response $response)
    {
        if ($this->_config['continue']) {
            return false;
        }
        if (is_string($this->_config['unauthorized'])) {
         // @codingStandardsIgnoreStart
            throw new $this->_config['unauthorized'];
         // @codingStandardsIgnoreEnd
        }
        $message = __d('authenticate', 'You are not authenticated.');
        throw new HttpException($message, $this->_config['unauthorized']);
    }