Multimaps.index(stringToObject.values().iterator(), Functions.toStringFunction());
    assertEquals(stringToObject, outputMap);
  }

  public void testIndex_ordering() {
    Multimap<Integer, String> expectedIndex =
        new ImmutableListMultimap.Builder<Integer, String>()
            .put(4, "Inky")
            .put(6, "Blinky")
            .put(5, "Pinky")
            .put(5, "Pinky")
            .put(5, "Clyde")