public async void TicketId_Create_Valid_Reference()
        {
            Mock <ISaleTicketsRepository> saleTicketsRepository = new Mock <ISaleTicketsRepository>();

            saleTicketsRepository.Setup(x => x.TicketByTicketId(It.IsAny <int>())).Returns(Task.FromResult <Ticket>(new Ticket()));

            var validator = new ApiSaleTicketsServerRequestModelValidator(saleTicketsRepository.Object);
            await validator.ValidateCreateAsync(new ApiSaleTicketsServerRequestModel());

            validator.ShouldNotHaveValidationErrorFor(x => x.TicketId, 1);
        }
        public async void SaleId_Update_Valid_Reference()
        {
            Mock <ISaleTicketsRepository> saleTicketsRepository = new Mock <ISaleTicketsRepository>();

            saleTicketsRepository.Setup(x => x.SaleBySaleId(It.IsAny <int>())).Returns(Task.FromResult <Sale>(new Sale()));

            var validator = new ApiSaleTicketsServerRequestModelValidator(saleTicketsRepository.Object);
            await validator.ValidateUpdateAsync(default(int), new ApiSaleTicketsServerRequestModel());

            validator.ShouldNotHaveValidationErrorFor(x => x.SaleId, 1);
        }