code: func (l *lcowfs) startVM() error {
  	l.Lock()
  	defer l.Unlock()
  	if l.currentSVM != nil {
  		return nil
  	}
  
  	svm, err := l.d.startServiceVMIfNotRunning(l.vmID, l.mappedDisks, fmt.Sprintf("lcowfs.startVM"))
  	if err != nil {
  		return err
  	}
  
  	if err = svm.createUnionMount(l.root, l.mappedDisks...); err != nil {
  		return err
  	}
  	l.currentSVM = svm
  	return nil
  }
docs: // Helper functions