public function deleteRoleAction($group_id = null, $privilege_controller = null)
 {
     //lấy group_id theo group_name
     $group = \Modules\Backend\Models\Permission_group::findFirst(array("conditions" => "id = ?1", "bind" => array(1 => $group_id), "columns" => "id,name"));
     // lấy mã privilege_id theo privilege_controller
     $privilege = \Modules\Backend\Models\Permission_privilege::find(array("conditions" => "controller = ?1", "bind" => array(1 => $privilege_controller), "columns" => "id,controller"));
     if ($group && $privilege) {
         foreach ($privilege as $key => $value) {
             $item = \Modules\Backend\Models\Permission_group_privilege::findFirst(array("conditions" => "privilege_id = ?1 AND group_id = ?2", "bind" => array(1 => $value->id, 2 => $group->id)));
             if (count($item) > 0 && !empty($item)) {
                 $this->delete($item->id);
             }
         }
     }
     $this->flash->success("Thành công!");
     $this->redirect(array("action" => "index"));
 }