code: func (d *Peer) handlePeersMsg(msg *peersMsg) error {
  	// register all addresses
  	if len(msg.Peers) == 0 {
  		return nil
  	}
  
  	for _, a := range msg.Peers {
  		d.seen(a)
  		NotifyPeer(a, d.kad)
  	}
  	return d.kad.Register(msg.Peers...)
  }
docs: // handlePeersMsg called by the protocol when receiving peerset (for target address)
  // list of nodes ([]PeerAddr in peersMsg) is added to the overlay db using the
  // Register interface method