adding an element to the end of a linked list java

1class Node {
2    Object data;
3    Node next;
4    Node(Object d,Node n) {
5        data = d ;
6        next = n ;
7       }
8
9   public static Node addLast(Node header, Object x) {
10       // save the reference to the header so we can return it.
11       Node ret = header;
12
13       // check base case, header is null.
14       if (header == null) {
15           return new Node(x, null);
16       }
17
18       // loop until we find the end of the list
19       while ((header.next != null)) {
20           header = header.next;
21       }
22
23       // set the new node to the Object x, next will be null.
24       header.next = new Node(x, null);
25       return ret;
26   }
27}