code: func (r *restMappingError) Message() string {
  	versionKind := fmt.Sprintf("%s/%s", r.version, r.kind)
  	errMsg := fmt.Sprintf("unable to get REST mapping for %s. ", versionKind)
  	errMsg += fmt.Sprintf(" If %s is an invalid resource, then you should manually remove ownerReferences that refer %s objects.", versionKind, versionKind)
  	return errMsg
  }
docs: // Message prints more details