code: func (auth *AuthProxy) GetUserIDViaCache() (int64, error) {
  	var (
  		cacheKey    = auth.getKey()
  		userID, err = auth.store.Get(cacheKey)
  	)
  
  	if err != nil {
  		return 0, err
  	}
  
  	return userID.(int64), nil
  }
docs: // GetUserIDViaCache gets the user from cache