mongodb数据库执行bee命令报错

func (this *AuthController) Get() {
  req, err := base64.URLEncoding.DecodeString(this.GetString("req"))
  var reqStr string
  if err != nil {
    reqStr = ""
  } else {
    reqStr = string(req)
  }
  this.Data["json"] = errors.Issue("You need login first",
    errors.E_TYPE_SERVICE + errors.E_MODULE_ANY + errors.E_DETAIL_NEED_LOGIN,
    reqStr)
  this.ServeJson()
}

controllers
controllers/auth.go:37: this.ServeJson undefined (type *AuthController has no field or method ServeJson)