code: func newStatusCodeRecoder(rw http.ResponseWriter, status int) statusCodeRecoder {
  	recorder := &statusCodeWithoutCloseNotify{rw, status}
  	if _, ok := rw.(http.CloseNotifier); ok {
  		return &statusCodeWithCloseNotify{recorder}
  	}
  	return recorder
  }
docs: // newStatusCodeRecoder returns an initialized statusCodeRecoder.