new long[] {MAX_VALUE, MAX_VALUE},
            new long[] {MAX_VALUE, MAX_VALUE, MAX_VALUE});

    Comparator<long[]> comparator = Longs.lexicographicalComparator();
    Helpers.testComparator(comparator, ordered);
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testLexicographicalComparatorSerializable() {

    assertSame(Ordering.natural(), copyFromSorted.valueComparator());
    assertSame(Ordering.natural(), copyFromSorted.get(1.0).comparator());
  }

  public void testComparators() {
    TreeMultimap<String, Integer> multimap = TreeMultimap.create();
    assertEquals(Ordering.natural(), multimap.keyComparator());
    assertEquals(Ordering.natural(), multimap.valueComparator());
  }