test.cs

// create new merge data
Order order = new Order()
{
    OrderID = 123,
    Customer = new Customer()
    {
        Name = "Peter Welch"
    },
    OrderItems = new List<OrderItem>()
    {
        new OrderItem() {
            Product = new Product() {
                Name = "Product A" },
            Quantity = 2 }
    }
};

// create a new instance of the DataSourceManager
dsManager = new DataSourceManager();

// load the data source
dsManager.LoadSingleObject(order);