@Test
  public void testNull() {
    StaticIntervalTree<Double, Interval<Double>> tree = new StaticIntervalTree<Double, Interval<Double>>();
    try {
      tree.buildTree(null);
      Assert.fail();
    } catch (NullPointerException e) {

    }
    try {
      tree.fetchContainingIntervals(new ArrayList<Interval<Double>>(),
                                    (Double) null);
      Assert.fail();
    } catch (NullPointerException e) {

    }
    try {
      tree.fetchContainingIntervals((Collection<Interval<Double>>) null, 0.0);
      Assert.fail();
    } catch (NullPointerException e) {

    }
    try {
      tree.fetchOverlappingIntervals(new ArrayList<Interval<Double>>(),
                                     (Interval<Double>) null);
      Assert.fail();
    } catch (NullPointerException e) {

    }
    try {
      tree.fetchOverlappingIntervals((Collection<Interval<Double>>) null,
                                     new Interval<Double>(0.0, true, 1.0, true));
      Assert.fail();
    } catch (NullPointerException e) {

    }
    Assert.assertFalse(tree.delete(null));
    Set<Interval<Double>> list = new HashSet<Interval<Double>>(masterClosed);
    list.add(null);
    try {
      tree.buildTree(list);
      Assert.fail();
    } catch (NullPointerException e) {

    }
    tree.buildTree(new HashSet<Interval<Double>>(masterClosed));
    try {
      tree.insert(null);
      Assert.fail();
    } catch (NullPointerException e) {

    }
  }