if (result == null){
Query query = em.createNamedQuery("Prefset.findByStatisticAndIndex");
Statistic stat = Statistic.getExists(statName);
query.setParameter("statistic", stat.getId());
query.setParameter("index", index);
Prefset prefset = (Prefset) query.getSingleResult();
result = prefset.getPrefname().getName();
}
return result;
}