实现一个链表称为循环链表的变化。链表应该能够被用来保留任何对象类型的数据。在一个循环链表的最后一个节点 相连字段不为空，而是指回第一个节点。你的执行应当至少包括以下操作：

1.添加到列表的末尾

2.删除指定项从列表

3.检索一个指定的项目从列表

4.使用Iterator遍历列表

5.退出程序.



您可能包括其他必要操作。

你已使用链表实施以上操作，编写一个应用程序代码来测试您的链表。选择一个对象（如图书，工人，零售项目等），定义为对象类，并创 建一个列表在这些对象。允许您的应用程序代码来演示的所有链表定义的操作使用。-required to implement a variation of the linked list ADT called a circular linked list. The linked list should be able to be used to keep any Object type data. The linked field of the last node of a circular linked list is not NULL, instead it points back to the first node. Your implementation should at least include the following operations:



　Add to the end of the list

　Remove a specified item from the list

　Retrieve a specified item from the list

　Traverse the list using an Iterator



You may include other operations deemed necessary.



Using the Linked List ADT that you have implemented above, write an application code to test your ADT. Choose an object (such as Book, Worker, Retail Item, etc), define the class for the object, and create a list to work on these objects. Allow your application code to demonstrate the use of all the operations defined in the Linked List ADT.