code: func (n *Network) PeersWithChannel(chanName string) []*Peer {
  	peers := []*Peer{}
  	for _, p := range n.Peers {
  		for _, c := range p.Channels {
  			if c.Name == chanName {
  				peers = append(peers, p)
  			}
  		}
  	}
  	return peers
  }
docs: // PeersWithChannel returns all Peer instances that have joined the named
  // channel.