code: func (s *StorageOverseer) Get(w http.ResponseWriter, r *http.Request) (value string, err error) {
  	sessID, err := s.options.getCookieValue(w, r)
  	if err != nil {
  		return "", errors.Wrap(err, "unable to get session id from cookie")
  	}
  
  	val, err := s.Storer.Get(sessID)
  	if err != nil {
  		return "", errors.Wrap(err, "unable to get session value")
  	}
  
  	return val, nil
  }
docs: // Get looks in the cookie for the session ID and retrieves the value string stored in the session.