code: func (q *QR) GetQRTicket(tq *Request) (t *Ticket, err error) {
  	accessToken, err := q.GetAccessToken()
  	if err != nil {
  		return
  	}
  
  	uri := fmt.Sprintf(qrCreateURL, accessToken)
  	response, err := util.PostJSON(uri, tq)
  	if err != nil {
  		err = fmt.Errorf("get qr ticket failed, %s", err)
  		return
  	}
  
  	t = new(Ticket)
  	err = json.Unmarshal(response, &t)
  	if err != nil {
  		return
  	}
  
  	return
  }
docs: // GetQRTicket 获取二维码 Ticket