code: func (sp *ServerPeer) newestBlock() (*chainhash.Hash, int32, error) {
  	bestHeader, bestHeight, err := sp.server.BlockHeaders.ChainTip()
  	if err != nil {
  		return nil, 0, err
  	}
  	bestHash := bestHeader.BlockHash()
  	return &bestHash, int32(bestHeight), nil
  }
docs: // newestBlock returns the current best block hash and height using the format
  // required by the configuration for the peer package.