code: func (c *Credentials) PublicData(options map[string]interface{}) (publicData interface{}, err error) {
  
  	// ensure the ID is a string
  	idValue := c.Map.Get(CredentialsKeyID).Data()
  	var idStringValue string
  	switch idValue.(type) {
  	case float64:
  		idStringValue = strconv.FormatFloat(idValue.(float64), 'g', -1, 64)
  	case string:
  		idStringValue = idValue.(string)
  	default:
  		idStringValue = fmt.Sprintf("%v", idValue)
  	}
  	c.Map.Set(CredentialsKeyID, idStringValue)
  
  	return c.Map, nil
  }
docs: // PublicData gets the storable data from this credentials object.