/**
  *
  * @param <String> $rev_id
  * @param <String> $sessionId
  * @param <Object> $model boModel
  * @param <Object> $blobCB=0 (should have been a causal barrier object but
  * not used yet)
  */
 static function storeModel($rev_id, $sessionId, $model, $blobCB)
 {
     wfDebugLog('p2p', ' -> store model into revid : ' . $rev_id . ' sessionid : ' . $sessionId . ' model : ' . $model->getText());
     try {
         $dao = new dao();
         $dao->storeModel($rev_id, $sessionId, $model, $blobCB);
     } catch (Exception $e) {
         die($e->getMessage());
         throw new MWException(__METHOD__ . ' db access problems');
     }
 }