Write the code necessary to convert the following sequence of ListNode objects:

list -> [1] -> [2] / 

Into this sequence of ListNode objects:

list -> [1] -> [2] -> [3] / 

Assume that you are using ListNode class as defined in lecture and section:

public class ListNode { public int data; // data stored in this node public ListNode next; // a link to the next node in the list public ListNode() { ... } public ListNode(int data) { ... } public ListNode(int data, ListNode next) { ... } }