public Order ChangeOrder(int orderId, Order orderToChange)
 {
     try
     {
         return _ordersRepository.AlterOrder(orderId, orderToChange);
     }
     catch (Exception ex)
     {
         //todo: log, handle gracefully
         throw;
     }
 }
 public Order AlterOrder(int orderId, Order orderToChange)
 {
     throw new NotImplementedException();
 }
 public Order Submit(Order newOrder)
 {
     try
     {
         return _ordersRepository.AddOrder(newOrder);
     }
     catch (Exception ex)
     {
         //todo: log, handle gracefully
         throw;
     }
 }
 public Order AddOrder(Order newOrder)
 {
     throw new NotImplementedException();
 }