public static void main(String[] args) {
    String[] data = new String[] {"1", "2", "3", "4", "5", "6"};
    Node head = new Node(data[0], null);
    Node current = head;
    for (int i = 1; i < data.length; i++) {
      Node tmp = new Node(data[i], null);
      current.setNext(tmp);
      current = tmp;
    }

    C3_5_ReverseLinkedList runner = new C3_5_ReverseLinkedList();
    int k = 3;
    head = runner.reverse(head, k);
    while (head != null) {
      System.out.println(head.getValue() + " ");
      head = head.next();
    }
  }