protected function addListSortCriteria($c)
 {
     if ($sort_column = $this->session->getAttribute('sort', null, 'sf_admin/opp_storici/sort')) {
         $sort_column = OppPoliticianHistoryCachePeer::translateFieldName($sort_column, BasePeer::TYPE_FIELDNAME, BasePeer::TYPE_COLNAME);
         if ($this->session->getAttribute('type', null, 'sf_admin/opp_storici/sort') == 'asc') {
             $c->addAscendingOrderByColumn($sort_column);
         } else {
             $c->addDescendingOrderByColumn($sort_column);
         }
     }
 }