@Test
  public void testClear() {
    MyTreeSet test = new MyTreeSet();
    test.add(1);
    test.add(2);
    test.add(3);
    test.add(4);
    // Size should be 4
    System.out.println(test.size());

    test.clear();

    // Size should be 0
    System.out.println(test.size());
  }