code: func callback(service models.DeviceService, id string, action string, actionType models.ActionType) error {
  	client := &http.Client{}
  	url := service.Addressable.GetCallbackURL()
  	if len(url) > 0 {
  		body, err := getBody(id, actionType)
  		if err != nil {
  			return err
  		}
  		req, err := http.NewRequest(string(action), url, bytes.NewReader(body))
  		if err != nil {
  			return err
  		}
  		req.Header.Add("Content-Type", "application/json")
  
  		go makeRequest(client, req)
  	} else {
  		LoggingClient.Info("callback::no addressable for " + service.Name)
  	}
  	return nil
  }
docs: // Make the callback for the device service