public void Assure_confirmation_message_is_sent_to_the_user()
{
var messageSenderMock = new MessageSenderMock();
var shoppingCart = new ShoppingCart(new EmailMessageSenderAdapter());
shoppingCart.PlaceOrder();
Assert.AreEqual(1, messageSenderMock.SendCallCount);
}
static void Main(string[] args)
{
var cart = new ShoppingCart(new EmailMessageSenderAdapter());
cart.PlaceOrder();
}