public function build()
    {
        $response = $this->_response;
        if (empty($this->_origin)) {
            return $response;
        }

        if (isset($this->_headers['Access-Control-Allow-Origin'])) {
            foreach ($this->_headers as $key => $value) {
                $response = $response->withHeader($key, $value);
            }
        }

        return $response;
    }