public void TestAll()
        {
            var service = new RecyclableProductService();
            var product = service.GetProductByBarcode("5900120016378");

            Assert.NotEmpty(service.GetAllProducts().SelectMany(p => p.Instructions).Select(i => i.Category));
        }
        public void HappyDay()
        {
            var service = new RecyclableProductService();
            var product = service.GetProductByBarcode("5900120016378");

            Assert.NotEmpty(product.Instructions.First().ItemName);
        }
        public void FindMilk()
        {
            var service = new RecyclableProductService();
            var product = service.FindProduct("milk");

            Assert.NotEmpty(product.Instructions.First().ItemName);
            Assert.Equal("5900120016378", product.Code);
        }