src/Request.php
public function render()
    {
        if ( ! $post = $this->post())
        {
            $body = $this->body;
        }
        else
        {
            $this->headers('content-type', 'application/x-www-form-urlencoded; charset=' . $this->charset);
            $body = http_build_query($post, null, '&');
        }

        $this->headers('content-length', (string) $this->contentLength);

        if (Base::$expose)
        {
            $this->headers('user-agent', Base::version());
        }

        if ($this->_cookies)
        {
            $cookieString = [];

            // Parse each
            foreach ($this->_cookies as $key => $value)
            {
                $cookieString[] = $key . '=' . $value;
            }

            // 创建cookie字符串
            $this->headers('cookie', implode('; ', $cookieString));
        }

        $output = $this->method . ' ' . $this->uri . ' ' . $this->protocol . "\r\n";
        $output .= $this->message->headerLines;
        $output .= $body;

        return $output;
    }
public function render()
    {
        if ( ! $post = $this->post())
        {
            $body = $this->body;
        }
        else
        {
            $this->headers('content-type', 'application/x-www-form-urlencoded; charset=' . $this->charset);
            $body = http_build_query($post, null, '&');
        }

        $this->headers('content-length', (string) $this->contentLength);

        if (Base::$expose)
        {
            $this->headers('user-agent', Base::version());
        }

        if ($this->_cookies)
        {
            $cookieString = [];

            // Parse each
            foreach ($this->_cookies as $key => $value)
            {
                $cookieString[] = $key . '=' . $value;
            }

            // 创建cookie字符串
            $this->headers('cookie', implode('; ', $cookieString));
        }

        $output = $this->method . ' ' . $this->uri . ' ' . $this->protocol . "\r\n";
        $output .= $this->message->headerLines;
        $output .= $body;

        return $output;
    }
渲染请求，保存：协议、头部、内容主体

@return  string