public function findRunningChangeset()
    {
        $qb = $this->createQueryBuilder('ac')
            ->select('ac')
            ->where('ac.status = :status')
            ->addOrderBy('ac.id', 'ASC')
            ->setMaxResults(1)
            ->setParameter('status', AclChangeset::STATUS_RUNNING);

        return $qb->getQuery()->getOneOrNullResult();
    }