Some collections have suppliers: a bakery, for example, may supply certain breads, cookies, cakes and pies; a financial report may supply certain data, statistics, tables, and reports. The Supplier class is used to enumerate items that a collection contained at the time of the supplier's creation. For example, this class contains methods to verify if an item is available from a supplier (Does the Pie-by-Night Bakery sell chocolate cake?). Another method returns the index of the current item in a collection (What is the position of the apple pie record?). Others return the current collection item in a collection object, and the next item in the collection.