code: public static function findActiveBySourceAndParent($strSource, $intParent, array $arrOptions=array())
  	{
  		$t = static::$strTable;
  
  		return static::findBy(array("$t.source=? AND $t.parent=? AND $t.active='1'"), array($strSource, $intParent), $arrOptions);
  	}
docs: Find active subscriptions by their source table and parent ID
  
  @param string  $strSource  The source element
  @param integer $intParent  The parent ID
  @param array   $arrOptions An optional options array
  
  @return Collection|CommentsNotifyModel[]|CommentsNotifyModel|null A collection of models or null if there are no active subscriptions