Ordering.<Double>natural().reverse().nullsFirst();

  /**
   * Test that creating one TreeMultimap from another does not copy the comparators from the source
   * TreeMultimap.
   */
  public void testCreateFromTreeMultimap() {
    Multimap<Double, Double> tree = TreeMultimap.create(KEY_COMPARATOR, VALUE_COMPARATOR);
    tree.put(1.0, 2.0);
    tree.put(2.0, 3.0);
    tree.put(3.0, 4.0);
    tree.put(4.0, 5.0);