public void TestGetAllProducts()
        {
            // repare
            var catalogus = new ProductCatalogus();

            // test
            var allProducts = catalogus.GetAllProducts();

            // validate
            Assert.IsNotNull(allProducts);
            Assert.AreEqual(03, allProducts.Count);
            Assert.AreEqual("Buy this product: It is sick!", allProducts[0].Description);
        }
        public void TestFindProductForBarcode()
        {
            // repare
            var catalogus = new ProductCatalogus();

            // test
            var test04   = catalogus.FindProductForBarcode("04");
            var test01   = catalogus.FindProductForBarcode("01");
            var testKaas = catalogus.FindProductForBarcode("kaas");

            // validate
            Assert.IsNull(test04);

            Assert.IsNotNull(test01);
            Assert.AreEqual("01", test01.Barcode);

            Assert.IsNull(testKaas);
        }