事件:'http.client.request.created'
【Event: 'http.client.request.created'】
request<http.ClientRequest>
当客户端创建请求对象时触发。与 http.client.request.start 不同,此事件在请求发送之前触发。
【Emitted when client creates a request object.
Unlike http.client.request.start, this event is emitted before the request has been sent.】