public IEnumerable <OrderDetail> GetOrders()
        {
            var orders  = _order.GetData();
            var product = _products.GetData();
            List <OrderDetail> contain = new List <OrderDetail>();

            product.ForEach(x => {
                if (orders.Any(g => g.productId == x.productId))
                {
                    contain.Add(new OrderDetail()
                    {
                        product = x,
                        order   = orders.Where(g => g.productId == x.productId)
                    });
                }
            });
            return(contain);
        }
 public IEnumerable <Product> GetProducts()
 {
     return(_products.GetData());
 }