Source code location: ./composite_data_bound_control/book.cs

public class Book
{
    string title = null;
    double price = 0.0;

    private Book () { }
    public Book (string title, double price)
    {
        this.title = title;
        this.price = price;
    }

    public string Title { get { return this.title; } }
    public double Price { get { return this.price; } }
}