code: func (s Session) sessionDataFromObject(key string, newValue interface{}) (result interface{}, err error) {
  	result, err = s.convertSessionData(key, newValue)
  	if err != nil {
  		return
  	}
  	s[key] = result
  	return
  }
docs: // Unpack the object from the session map and store it in the session when done, if no error occurs