assertTrue(reserializedValues instanceof ImmutableCollection);
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testKeySetIsSerializable_regularImmutableMap() {
    class NonSerializableClass {}

    Map<String, NonSerializableClass> map =
        RegularImmutableMap.create(1, new Object[] {"one", new NonSerializableClass()});