code: func (resp *Response) BodyWriteTo(w io.Writer) error {
  	if resp.bodyStream != nil {
  		_, err := copyZeroAlloc(w, resp.bodyStream)
  		resp.closeBodyStream()
  		return err
  	}
  	_, err := w.Write(resp.bodyBytes())
  	return err
  }
docs: // BodyWriteTo writes response body to w.