code: func (s *ChainService) UpdatePeerHeights(latestBlkHash *chainhash.Hash,
  	latestHeight int32, updateSource *ServerPeer) {
  
  	select {
  	case s.peerHeightsUpdate <- updatePeerHeightsMsg{
  		newHash:    latestBlkHash,
  		newHeight:  latestHeight,
  		originPeer: updateSource,
  	}:
  	case <-s.quit:
  		return
  	}
  }
docs: // UpdatePeerHeights updates the heights of all peers who have have announced
  // the latest connected main chain block, or a recognized orphan. These height
  // updates allow us to dynamically refresh peer heights, ensuring sync peer
  // selection has access to the latest block heights for each peer.