public void Can_Retrieve_Invoices_By_Customer_From_The_Index()
        {
            //// Arrange

            var customer = PreTestDataWorker.CustomerService.CreateCustomerWithKey(
                "rusty",
                "firstName",
                "lastName",
                "*****@*****.**");

            var invoice1 = MockInvoiceDataMaker.InvoiceForInserting(_address, 300);

            invoice1.Items.Add(new InvoiceLineItem(LineItemType.Product, "test", "test", 1, 100));
            invoice1.Items.Add(new InvoiceLineItem(LineItemType.Product, "test2", "test2", 2, 100));
            ((Invoice)invoice1).CustomerKey = customer.Key;

            var invoice2 = MockInvoiceDataMaker.InvoiceForInserting(_address, 100);

            invoice2.Items.Add(new InvoiceLineItem(LineItemType.Product, "test", "test", 1, 100));
            ((Invoice)invoice2).CustomerKey = customer.Key;

            var invoice3 = MockInvoiceDataMaker.InvoiceForInserting(_address, 300);

            invoice3.Items.Add(new InvoiceLineItem(LineItemType.Product, "test2", "test2", 3, 100));
            ((Invoice)invoice3).CustomerKey = customer.Key;

            PreTestDataWorker.InvoiceService.Save(invoice1);
            PreTestDataWorker.InvoiceService.Save(invoice2);
            PreTestDataWorker.InvoiceService.Save(invoice3);

            //// Act
            var merchello = new MerchelloHelper();

            var invoices = merchello.InvoicesByCustomer(customer.Key);

            //// Assert
            Assert.NotNull(invoices, "invoices was null");
            Assert.IsTrue(invoices.Any());
            Assert.AreEqual(3, invoices.Count());
        }