code: func (d *Peer) NotifyPeer(a *BzzAddr, po uint8) {
  	// immediately return
  	if (po < d.getDepth() && pot.ProxCmp(d.kad.BaseAddr(), d, a) != 1) || d.seen(a) {
  		return
  	}
  	resp := &peersMsg{
  		Peers: []*BzzAddr{a},
  	}
  	go d.Send(context.TODO(), resp)
  }
docs: // NotifyPeer notifies the remote node (recipient) about a peer if
  // the peer's PO is within the recipients advertised depth
  // OR the peer is closer to the recipient than self
  // unless already notified during the connection session