public void RetrieveTestIterator()
        {
            // Arrange
            var repository = new VendorRepository();
            var expected = new List<Vendor>();

            expected.Add(new Vendor() { CompanyName = "IBM", Email = "*****@*****.**", VendorId = 12345 });
            expected.Add(new Vendor() { CompanyName = "GE", Email = "*****@*****.**", VendorId = 54321 });

            // Act
            var vendorIterator = repository.RetrieveWithIterator();

            foreach (var item in vendorIterator)
            {
                Console.WriteLine(item);
            }

            var actual = vendorIterator.ToList();

            // Assert
            CollectionAssert.AreEqual(expected, actual);
        }