public void AppliedPromotionIsSetCorrectly()
        {
            _mockPromotionRepository.Setup(x => x.All()).Returns(GetTestPromotions());

            var productC = new Product("C", 20m);
            var productD = new Product("D", 15m);

            _sut.AddProduct(productC);
            _sut.AddProduct(productD);

            var appliedPromotionInfo = _sut.ApplyPromotions();

            appliedPromotionInfo.Discount.ShouldBe(5);
        }