public static void main(String[] args) {
OrderClient client = new OrderClient();
List<LineItem> lineItems = new ArrayList<LineItem>();
String itemName = "cheese";
lineItems.add(new LineItem(itemName, 2, 1000000L, "USD"));
Cart cart = new Cart(lineItems, "Hungry Bird", "4111-1111-1111-1111");
cart = client.createCart(cart);
Order order = client.placeOrder(cart);
System.out.println("Placed order: " + gson.toJson(order));