code: func handleGetBestBlock(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (interface{}, error) {
  	// All other "get block" commands give either the height, the
  	// hash, or both but require the block SHA.  This gets both for
  	// the best block.
  	best := s.cfg.Chain.BestSnapshot()
  	result := &btcjson.GetBestBlockResult{
  		Hash:   best.Hash.String(),
  		Height: best.Height,
  	}
  	return result, nil
  }
docs: // handleGetBestBlock implements the getbestblock command.