public void CheckChoosePaymentType()
{
Mock <IOrderRepository> repositoryMock = new Mock <IOrderRepository>();
ShopService ss = new ShopService(repositoryMock.Object);
var order = OrderObjectMother.CreateOrderWithNoItems();
string paymentType = "newPaymentType";
ss.ChoosePaymentType(order, paymentType);
Assert.AreEqual(order.PaymentType, paymentType);
}