code: func (wh Webhook) MarshalJSON() ([]byte, error) {
  	data := jsonWebhook{
  		ID:        wh.ID,
  		URL:       wh.URL,
  		Token:     wh.Token,
  		CreatedAt: wh.CreatedAt.Format(time.RFC3339),
  		UpdatedAt: wh.UpdatedAt.Format(time.RFC3339),
  	}
  	return json.Marshal(data)
  }
docs: // MarshalJSON implements the json.Marshaler interface.