public function TopMost()
    {
        $sql = Access::SqlBuilder();
        $tblParams = PageUrlParameter::Schema()->Table();
        $where = $sql->Equals($tblParams->Field('PageUrl'), $sql->Value($this->pageUrl->GetID()))
                ->And_($sql->IsNull($tblParams->Field('Previous')));
        
        return PageUrlParameter::Schema()->First($where);
    }