code: func (b *FusisBalancer) cleanup() error {
  	b.flushVips()
  
  	if out, err := exec.Command("ipvsadm", "--clear").CombinedOutput(); err != nil {
  		log.Fatal(fmt.Errorf("Running ipvsadm --clear failed with message: `%s`, error: %v", strings.TrimSpace(string(out)), err))
  	}
  
  	return nil
  }
docs: // Utility method to cleanup state for tests