tree.put(1.0, 2.0);
    tree.put(2.0, 3.0);
    tree.put(3.0, 4.0);
    tree.put(4.0, 5.0);

    SortedSetMultimap<Double, Double> sorted = Multimaps.unmodifiableSortedSetMultimap(tree);
    TreeMultimap<Double, Double> copyFromSorted = TreeMultimap.create(sorted);
    assertEquals(tree, copyFromSorted);
    assertSame(Ordering.natural(), copyFromSorted.keyComparator());

          .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())

          .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(