private void TestAddProduct(List <Product> currentProducts, Product productToAdd, List <Product> expectedProducts)
        {
            // Arrange
            var objectStorage = new ObjectStorageBuilder()
                                .SetupRead(currentProducts)
                                .SetupWrite(expectedProducts)
                                .Build();

            var sut = new RecentProductsService(objectStorage);

            // Act
            sut.AddProduct(productToAdd).Wait();

            // Assert
            objectStorage.AsMock().Verify();
        }