Implement the addLast method in this simplified LinkedList class.

Complete the following file:

LinkedList.java

/** A linked list is a sequence of nodes with efficient element insertion and removal. This class contains a subset of the methods of the standard java.util.LinkedList class. */ public class LinkedList { private Node first; /** Constructs an empty linked list. */ public LinkedList() { first = null; } /** Adds an element to the front of the linked list. @param element the element to add */ public void addFirst(Object element) { Node newNode = new Node(); newNode.data = element; newNode.next = first; first = newNode; } /** Adds an element to the end of the linked list. @param element the element to add */ public void addLast(Object element) { // your work here } public String toString() { String r = "["; for (Node current = first; current != null; current = current.next) { if (current != first) r = r + ","; r = r + current.data; } return r + "]"; } class Node { public Object data; public Node next; } // This method is used to check your work public static String check(String[] first, String[] last) { LinkedList list = new LinkedList(); for (String s : last) list.addLast(s); for (String s : first) list.addFirst(s); return list.toString(); } }