public function getLogEntriesQueryRoot($entity, $rootVersion = null)
    {
        $wrapped = new EntityWrapper($entity, $this->_em);
        $objectClass = $wrapped->getMetadata()->name;
        $meta = $this->getClassMetadata();
        $dql = "SELECT log FROM {$meta->name} log";
        $dql .= " WHERE log.objectId = :objectId";
        $dql .= " AND log.objectClass = :objectClass";
        $dql .= " AND log.rootVersion <= :rootVersion";
        $dql .= " ORDER BY log.version DESC";

        $objectId = $wrapped->getIdentifier();
        $q = $this->_em->createQuery($dql);
        $q->setParameters(compact('objectId', 'objectClass', 'rootVersion'));

        return $q;
    }