public void AddOrderLine(Product product, int quantity, double price)
{
SaleOrderLine orderLine = new SaleOrderLine(product, quantity, price);
OrderLines.Add(orderLine);
}
public void AddOrderLine(Product product, int quantity, int price)
{
SaleOrderLine saleOrderLine = new SaleOrderLine(product, quantity, price);
orderlines.Add(saleOrderLine);
}