/**
  * Update groups of this backend, optionally limited using a filter
  *
  * @param   string  $target
  * @param   array   $data
  * @param   Filter  $filter
  *
  * @throws  StatementException  In case the operation has failed
  */
 public function update($target, array $data, Filter $filter = null)
 {
     $data['last_modified'] = time();
     parent::update($target, $data, $filter);
 }