code: public function setId ($group, $id)
  	{
  		$this->sGroup = $group;
  		$this->sId = $id;
  		
  		$this->sXML['id'] = $id;
  		$this->sXML['group'] = $group;
  	}
docs: /*
  Set a notifications group and ID.
  For example: group "messages" contains "sent" and "received"