code: public static function findBySourceParentAndEmail($strSource, $intParent, $strEmail, array $arrOptions=array())
  	{
  		$t = static::$strTable;
  
  		return static::findOneBy(array("$t.source=? AND $t.parent=? AND $t.email=?"), array($strSource, $intParent, $strEmail), $arrOptions);
  	}
docs: Find a subscription by its source table, parent ID and e-mail address
  
  @param string  $strSource  The source element
  @param integer $intParent  The parent ID
  @param string  $strEmail   The e-mail address
  @param array   $arrOptions An optional options array
  
  @return CommentsNotifyModel|null The model or null if there are no subscriptions