assertEquals(Ordering.natural(), multimap.keyComparator());
    assertEquals(Ordering.natural(), multimap.valueComparator());
    SerializableTester.reserializeAndAssert(multimap);
  }

  public void testTreeMultimapAsMapSorted() {
    TreeMultimap<String, Integer> multimap = createPopulate();
    SortedMap<String, Collection<Integer>> asMap = multimap.asMap();
    assertEquals(Ordering.natural(), asMap.comparator());