code: func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
  	apiserver, ok := obj.(*wardle.Flunder)
  	if !ok {
  		return nil, nil, fmt.Errorf("given object is not a Flunder")
  	}
  	return labels.Set(apiserver.ObjectMeta.Labels), SelectableFields(apiserver), nil
  }
docs: // GetAttrs returns labels.Set, fields.Set, and error in case the given runtime.Object is not a Flunder