elmah.ir-post120-code3.cs

 [Test]
  public void WhenAValidCustomerPlacesAValidOrderAnOrderShouldBePlaced()
  {
    //Arrange
    var shoppingCart = new ShoppingCart();
    shoppingCart.Items.Add(new ShoppingCartItem { ItemId = Guid.NewGuid(), Quantity = 1 });
    var customerId = Guid.NewGuid();

    //Act
    _orderService.PlaceOrder(customerId, shoppingCart);
  }