public void Init()
 {
     Order = new Order();
     Order.Items.Add(new Item { Title = "Apple", Price = 10 });
     Order.Items.Add(new Item { Title = "Orange", Price = 10 });
     Order.Items.Add(new Item { Title = "Banana", Price = 10 });
 }
 public double Calculate(Order order)
 {
     return order.TotalPrice * 3;
 }
 public double Calculate(Order order)
 {
     return Calculator.Calculate(order);
 }