public List<Event> list() {
   session = HibernateUtil.getSessionFactory().openSession();
   transaction = session.beginTransaction();
   events = (List<Event>) session.createQuery("from Event").list();
   participationService.setParticipants(events);
   return events;
 }
 public Map<Integer, List<Team>> getParticipants() {
   return participationService.getParticipants();
 }