code: func (e *ErrGroupDiscoveryFailed) Error() string {
  	var groups []string
  	for k, v := range e.Groups {
  		groups = append(groups, fmt.Sprintf("%s: %v", k, v))
  	}
  	sort.Strings(groups)
  	return fmt.Sprintf("unable to retrieve the complete list of server APIs: %s", strings.Join(groups, ", "))
  }
docs: // Error implements the error interface