code: func (service *Service) getUserLoggingIn(request *http.Request) (username string, err error) {
  	loginSession, err := service.GetSession(request, SessionLogin, "loginsession")
  	if err != nil {
  		log.Error(err)
  		return
  	}
  	savedusername := loginSession.Values["username"]
  	if savedusername != nil {
  		username, _ = savedusername.(string)
  	}
  	return
  }
docs: //getUserLoggingIn returns an user trying to log in, or an empty string if there is none