gistfile1.cs

public IEnumerable<Order> GetApprovedOrders()
{
    string address = "http://contoso.com/orders";
    HttpClient client = new HttpClient(address);
    WebQuery<Order> orders = client.CreateQuery<Contact>();
    return orders.Where<Order>(o=>o.State == OrderState.Approved). OrderBy(o=o.OrderID);
}