code: func (c *Client) GetMemberID(peerURL string) (uint64, error) {
  	cli, err := clientv3.New(clientv3.Config{
  		Endpoints:   c.Endpoints,
  		DialTimeout: 30 * time.Second,
  		TLS:         c.TLS,
  	})
  	if err != nil {
  		return 0, err
  	}
  	defer cli.Close()
  
  	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
  	resp, err := cli.MemberList(ctx)
  	cancel()
  	if err != nil {
  		return 0, err
  	}
  
  	for _, member := range resp.Members {
  		if member.GetPeerURLs()[0] == peerURL {
  			return member.GetID(), nil
  		}
  	}
  	return 0, nil
  }
docs: // GetMemberID returns the member ID of the given peer URL