public async Task DeleteMemberFromEvent(Guid eventId, Guid memberId)
{
var @event = await _eventRepository.Get(eventId);
EnsureEventExists(@event);
var member = await _memberRepository.Get(memberId);
EnsureMemberExists(member);
await _memberRepository.DeleteMemberFromEvent(@event.Id, memberId);
await EnsureMemberDeletedInDataBase();
}
