Serializer serializer = new Persister(strategy, matcher);
matcher.bind(Integer.class, IntegerTransform.class);
registry.bind(User.class, new UserConverter(usersDao, usersMap));
registry.bind(Room.class, new RoomConverter(roomDao, roomsMap));
registry.bind(PollType.class, new PollTypeConverter(pollManager));
registry.bind(Date.class, DateConverter.class);
List<RoomPoll> list = readList(serializer, f, "roompolls.xml", "roompolls", RoomPoll.class, true);
for (RoomPoll rp : list) {
if (rp.getRoom() == null || rp.getRoom().getRooms_id() == null) {