code: func RecordChangeCause(obj runtime.Object, changeCause string) error {
  	meta, err := api.ObjectMetaFor(obj)
  	if err != nil {
  		return err
  	}
  	if meta.Annotations == nil {
  		meta.Annotations = make(map[string]string)
  	}
  	meta.Annotations[kubectl.ChangeCauseAnnotation] = changeCause
  	return nil
  }
docs: // RecordChangeCause annotate change-cause to input runtime object.