Add sample data structure in comments.
Add sample data structure in comments.

agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart,agreatfool/Cart