public void can_save_order()
        {
            var purchaseOrder = new PurchaseOrder
            {
                Date   = DateTime.Now,
                Number = "N1"
            };

            modifyOrderModel.Persist(purchaseOrder);
            Assert.That(purchaseOrder, Is.Not.Null);
            Assert.That(purchaseOrder.Id > 0);
        }
        void view_SaveButtonPressed(object sender, EventArgs e)
        {
            currentOrder.ClearLines();
            currentOrder.AddLines(View.OrderLines);

            modifyOrderModel.Persist(currentOrder);
        }