code: func (gs *genericStore) close() error {
  	var err error
  	var lerr error
  
  	for _, cs := range gs.channels {
  		lerr = cs.Subs.Close()
  		if lerr != nil && err == nil {
  			err = lerr
  		}
  		lerr = cs.Msgs.Close()
  		if lerr != nil && err == nil {
  			err = lerr
  		}
  	}
  	return err
  }
docs: // close closes all stores. Store lock is assumed held on entry