5. Consider the singly-linked list implementation of our Bag ADT, which stores the elements in arbitrary order using a linked list. Given the following declaration of the Bag ADT, implement an Iterator for Bag. class ListNode \{int val; ListNode next; ListNode (int v)\{val=v; \}\} class ListBag implements Iterable private ListNode head = null; public Iterator < Integer > iterator (){/ Fill this in /} \} Fill in the implementation details of the method "iterator". Recall that the Iterator interface in Java has the following 2 public methods you have to implement:.