public List<Revision> findAllrevisions() {
        CriteriaBuilder cb = em.getCriteriaBuilder();
        CriteriaQuery<Revision> cq = cb.createQuery(Revision.class);
        Root<Revision> revisionRoot = cq.from(Revision.class);
        cq.select(revisionRoot);
        
        return em.createQuery(cq).getResultList();
        
       // TypedQuery<Revision> query1 = em.createQuery(
        //        "SELECT r FROM Revision r", Revision.class);
        //return query1.getResultList();