code: func (r *configs) Get(configID string) (*api.Config, error) {
  	r.mu.RLock()
  	defer r.mu.RUnlock()
  	if r, ok := r.m[configID]; ok {
  		return r, nil
  	}
  	return nil, fmt.Errorf("config %s not found", configID)
  }
docs: // Get returns a config by ID.  If the config doesn't exist, returns nil.