.put(SetMultimap.class, ImmutableSetMultimap.of())
          .put(ImmutableSetMultimap.class, ImmutableSetMultimap.of())
          .put(
              SortedSetMultimap.class,
              Multimaps.unmodifiableSortedSetMultimap(TreeMultimap.create()))
          .put(Multiset.class, ImmutableMultiset.of())
          .put(ImmutableMultiset.class, ImmutableMultiset.of())
          .put(SortedMultiset.class, ImmutableSortedMultiset.of())

   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      SortedSetMultimap<K, V> unmodifiableSortedSetMultimap(SortedSetMultimap<K, V> delegate) {
    if (delegate instanceof UnmodifiableSortedSetMultimap) {
      return delegate;
    }
    return new UnmodifiableSortedSetMultimap<>(delegate);
  }

  /**

          .put(SetMultimap.class, ImmutableSetMultimap.of())
          .put(ImmutableSetMultimap.class, ImmutableSetMultimap.of())
          .put(
              SortedSetMultimap.class,
              Multimaps.unmodifiableSortedSetMultimap(TreeMultimap.create()))
          .put(Multiset.class, ImmutableMultiset.of())
          .put(ImmutableMultiset.class, ImmutableMultiset.of())
          .put(SortedMultiset.class, ImmutableSortedMultiset.of())

      assertEquals(8, multimap.size());
    }

    Multimap<@Nullable String, @Nullable Integer> unmodifiable;
    if (multimap instanceof SortedSetMultimap) {
      unmodifiable =
          Multimaps.unmodifiableSortedSetMultimap(
              (SortedSetMultimap<@Nullable String, @Nullable Integer>) multimap);
    } else if (multimap instanceof SetMultimap) {
      unmodifiable =
          Multimaps.unmodifiableSetMultimap(