assertTrue(multimap.keySet() instanceof SortedSet);
    assertTrue(multimap.asMap() instanceof SortedMap);
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testNewListMultimapSerialization() {
    CountingSupplier<LinkedList<Integer>> factory = new ListSupplier();
    Map<Color, Collection<Integer>> map = Maps.newTreeMap();