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();
        }