code: func (cs *CryptoStore) CreateChannel(channel string) (*Channel, error) {
  	cs.Lock()
  	defer cs.Unlock()
  
  	c, err := cs.Store.CreateChannel(channel)
  	if err != nil {
  		return nil, err
  	}
  	cms, err := cs.newCryptoMsgStore(channel, c.Msgs)
  	if err != nil {
  		return nil, err
  	}
  	c.Msgs = cms
  	return c, nil
  }
docs: // CreateChannel implements the Store interface