code: public function scheduleUpdate(Contao\DataContainer $dc)
  	{
  		// Return if there is no ID
  		if (!$dc->id)
  		{
  			return;
  		}
  
  		/** @var Symfony\Component\HttpFoundation\Session\SessionInterface $objSession */
  		$objSession = Contao\System::getContainer()->get('session');
  
  		// Store the ID in the session
  		$session = $objSession->get('news_feed_updater');
  		$session[] = $dc->id;
  		$objSession->set('news_feed_updater', array_unique($session));
  	}
docs: Schedule a news feed update
  
  This method is triggered when a single news archive or multiple news
  archives are modified (edit/editAll).
  
  @param Contao\DataContainer $dc