public async Task CreateAsync(Guid id, string title, string description, string category, DateTime date, string city, string venue) { var activity = await _activityRepository.GetByIdAsync(id); if (activity != null) { throw new InfrastructureException(HttpStatusCode.Conflict, ErrorMessage.ActivityAlreadyExists); } activity = Activity.Create(id, title, description, category, date, city, venue); await _activityRepository.AddSingleAsync(activity); }