public void PlaceOrder_NoDeliveryDate()
{
// Arrange
var vendor = new Vendor();
var product = new Product(1, "Saw", "");
var expected = new OperationResult(true,
"Order from Acme, Inc\r\nProduct: Saw\r\nQuantity: 12" +
"\r\nInstructions: Deliver to Suite 42");
// Act
var actual = vendor.PlaceOrder(product, 12,
instructions: "Deliver to Suite 42");
// Assert
Assert.AreEqual(expected.Success, actual.Success);
Assert.AreEqual(expected.Message, actual.Message);
}