How to: Retrieve Many Objects At Once (LINQ to SQL)

Northwnd db = new Northwnd(@"northwnd.mdf");
DataLoadOptions ds = new DataLoadOptions();
ds.LoadWith<Customer>(c => c.Orders);
ds.LoadWith<Order>(o => o.OrderDetails);
db.LoadOptions = ds;

var custQuery =
    from cust in db.Customers
    where cust.City == "London" 
    select cust;

foreach (Customer custObj in custQuery)
{
    Console.WriteLine("Customer ID: {0}", custObj.CustomerID);
    foreach (Order ord in custObj.Orders)
    {
        Console.WriteLine("\tOrder ID: {0}", ord.OrderID);
        foreach (OrderDetail detail in ord.OrderDetails)
        {
            Console.WriteLine("\t\tProduct ID: {0}", detail.ProductID);
        }
    }
}