code: func (r *Router) updateChannelMembers() {
  	// TODO sleep a minute because slack can take a while
  	// fix this by having actually connectionDone events send to the router
  	time.Sleep(time.Minute)
  	for {
  		for _, gw := range r.Gateways {
  			for _, br := range gw.Bridges {
  				// only for slack now
  				if br.Protocol != "slack" {
  					continue
  				}
  				r.logger.Debugf("sending %s to %s", config.EventGetChannelMembers, br.Account)
  				if _, err := br.Send(config.Message{Event: config.EventGetChannelMembers}); err != nil {
  					r.logger.Errorf("updateChannelMembers: %s", err)
  				}
  			}
  		}
  		time.Sleep(time.Minute)
  	}
  }
docs: // updateChannelMembers sends every minute an GetChannelMembers event to all bridges.