public async Task InviteGuestToEvent(List <Guid> guestsToInvite, Guid idEventToInvite) { var eventToInvite = await _eventsRepository.GetEventAsync(idEventToInvite); var guests = await _guestsRepository.GetGuests(guestsToInvite); guests.ToList() .ForEach(g => eventToInvite.Invite(g)); await _guestsRepository.SaveChangeAsync(); }