code: func (daemon *Daemon) reloadLabels(conf *config.Config, attributes map[string]string) error {
  	// update corresponding configuration
  	if conf.IsValueSet("labels") {
  		daemon.configStore.Labels = conf.Labels
  	}
  
  	// prepare reload event attributes with updatable configurations
  	if daemon.configStore.Labels != nil {
  		labels, err := json.Marshal(daemon.configStore.Labels)
  		if err != nil {
  			return err
  		}
  		attributes["labels"] = string(labels)
  	} else {
  		attributes["labels"] = "[]"
  	}
  
  	return nil
  }
docs: // reloadLabels updates configuration with engine labels
  // and updates the passed attributes