code: func (c *testCluster) Stop() error {
  	c.cancel()
  	for _, n := range c.nodes {
  		if err := n.Stop(); err != nil {
  			return err
  		}
  	}
  	c.wg.Wait()
  	close(c.errs)
  	for err := range c.errs {
  		if err != nil {
  			return err
  		}
  	}
  	return nil
  }
docs: // Stop makes best effort to stop all nodes and close connections to them.