Doubling a Linked List

//couldn't find a better way to do this...

public void double2 ( ) {
  /* Invariant is L with 2 first ones and rest*/
  ListNode q, w;
  w = q = new ListNode (null);
  
  for (ListNode p = myHead; p != null; p = p.myRest) {
       
       q.myRest = new ListNode(p.myFirst, p);
       q = q.myRest.myRest;
       
               
     }
  myHead = w.myRest;
   /*ListNode p = myHead;
  ListNode p1 = myHead.myRest;
  ListNode p2 = myHead.myRest.myRest;
  
  myHead = new ListNode (p.myFirst, p);
  myHead.myRest.myRest = new ListNode (p1.myFirst, p1);
  myHead.myRest.myRest.myRest.myRest = new ListNode (p2.myFirst, p2);
   */
 }
 
 public void double3 ( ) {
  ListNode w;
  w = new ListNode (myHead.myFirst);
  for (ListNode p = myHead; p != null; p = p.myRest) {
   w.myRest= new ListNode(p.myFirst, p);
   w = w.myRest.myRest;
   System.out.println(this.toString());
  }
  myHead = new ListNode (myHead.myFirst, myHead);
 }