Multimap<String, Integer> unmod = Multimaps.unmodifiableMultimap(mod);
    assertNotSame(mod, unmod);
    assertSame(unmod, Multimaps.unmodifiableMultimap(unmod));
    ImmutableMultimap<String, Integer> immutable = ImmutableMultimap.of("a", 1, "b", 2, "a", 3);
    assertSame(immutable, Multimaps.unmodifiableMultimap(immutable));
    assertSame(immutable, Multimaps.unmodifiableMultimap((Multimap<String, Integer>) immutable));
  }

   */
  public static <K extends @Nullable Object, V extends @Nullable Object>
      Multimap<K, V> unmodifiableMultimap(Multimap<K, V> delegate) {
    if (delegate instanceof UnmodifiableMultimap || delegate instanceof ImmutableMultimap) {
      return delegate;
    }
    return new UnmodifiableMultimap<>(delegate);
  }

  /**
   * Simply returns its argument.
   *
   * @deprecated no need to use this

    assertOrderingReadOnly(multimap);
  }

  public void testOrderingUnmodifiable() {
    Multimap<String, Integer> multimap = initializeMultimap5();
    assertOrderingReadOnly(Multimaps.unmodifiableMultimap(multimap));
  }

  @J2ktIncompatible // Synchronized
  public void testOrderingSynchronized() {
    Multimap<String, Integer> multimap = initializeMultimap5();