@Test
  public void test() {
    Node root = new Node(5, null, null);
    IndexTree myTree = new IndexTree(root);
    myTree.addNode(new Node(4, null, null));
    myTree.addNode(new Node(6, null, null));

    Node elem = myTree.find(3);
    assertEquals(4, elem.getKey());
    assertEquals(myTree.noOfElements, 3);
    assertEquals(elem.cost, 2);
  }