public function TopMost()
    {
        $sql = Access::SqlBuilder();
        $tblCategory = Category::Schema()->Table();
        $where = $sql->Equals($tblCategory->Field('Archive'), $sql->Value($this->archive->GetID()))
                ->And_($sql->IsNull($tblCategory->Field('Previous')));
        
        return Category::Schema()->First($where);
    }