protected Map<Integer, UserData> persistInterests(List<Interest> objects, Map<Integer, UserData> users) throws Exception {
        for (Interest row : objects) {
            if (!users.containsKey(row.id)) {
                throw new Exception("The user is not readed yet");
            }
            UserData user = users.get(row.id);
            user.sport = row.favouriteSport;
            users.put(user.id, user);
        }
        return users;
    }