code: func (c *Client) Sync() error {
  	cli, err := clientv3.New(clientv3.Config{
  		Endpoints:   c.Endpoints,
  		DialTimeout: 20 * time.Second,
  		TLS:         c.TLS,
  	})
  	if err != nil {
  		return err
  	}
  	defer cli.Close()
  
  	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
  	err = cli.Sync(ctx)
  	cancel()
  	if err != nil {
  		return err
  	}
  	klog.V(1).Infof("etcd endpoints read from etcd: %s", strings.Join(cli.Endpoints(), ","))
  
  	c.Endpoints = cli.Endpoints()
  	return nil
  }
docs: // Sync synchronizes client's endpoints with the known endpoints from the etcd membership.