Insert at End
public void addLast(AnyType item)
{
if( head == null)
addFirst(item);
else
addLast(head, item);
}
private void addLast(Node<AnyType> node, AnyType item)
{
if(node.next != null) addLast(node.next, item);
else
node.next = new Node<AnyType>(item, null);
}