class GuestService {

    public List<Guest> getAllGuests() {
        CriteriaQuery<Guest> cq = this.em.getCriteriaBuilder().createQuery(Guest.class);
        cq.select(cq.from(Guest.class));
        return this.em.createQuery(cq).getResultList();
    }

    public  GuestService();
    @Inject public  GuestService(@Background Event<Guest> guestEvents);

}