Multimap<Color, Integer> multimap = Multimaps.newMultimap(map, factory);
    assertTrue(multimap.get(Color.BLUE) instanceof NavigableSet);
  }

  public void testNewMultimapValueCollectionMatchesList() {
    Supplier<LinkedList<Integer>> factory = new ListSupplier();
    Map<Color, Collection<Integer>> map = Maps.newEnumMap(Color.class);
    Multimap<Color, Integer> multimap = Multimaps.newMultimap(map, factory);

   *     key
   * @throws IllegalArgumentException if {@code map} is not empty
   */
  public static <K extends @Nullable Object, V extends @Nullable Object> Multimap<K, V> newMultimap(
      Map<K, Collection<V>> map, Supplier<? extends Collection<V>> factory) {
    return new CustomMultimap<>(map, factory);
  }