public void Add(Product product, uint quantity)
{
var existingLine = lines.FirstOrDefault(x => x.ProductId == product.Id);
if (existingLine != null)
existingLine.Quantity += quantity;
else
lines.Add(new Line(product.Id, product.Name, quantity));
}
public ProductDetails(Product product)
{
ProductId = product.Id;
ProductName = product.Name;
UnitPrice = product.UnitPrice;
}