code: func (lc *Lifecycle) NewChannelSubscription(channel string, queryCreator QueryCreator) (*Subscription, error) {
  	sub := &Subscription{
  		lc:           lc,
  		channel:      channel,
  		queryCreator: queryCreator,
  	}
  	// Initialize metadata for the channel.
  	// This loads metadata about all installed chaincodes
  	if err := lc.initMetadataForChannel(channel, queryCreator); err != nil {
  		return nil, errors.WithStack(err)
  	}
  	lc.fireChangeListeners(channel)
  	return sub, nil
  }
docs: // NewChannelSubscription subscribes to a channel