code: func (a Action) String() string {
  	switch a {
  	case Insert:
  		return "Insert"
  	case Delete:
  		return "Delete"
  	case Modify:
  		return "Modify"
  	default:
  		panic(fmt.Sprintf("unsupported action: %d", a))
  	}
  }
docs: // String returns the action as a human readable text.