public void IgnoredSubtypeTest()
    {
        var expected = new SuperclassContainerWithNoBinding
        {
            Superclass = new IgnoredSubtype()
        };

        Roundtrip(expected);
    }
    public void UnorderedSubtypeTest()
    {
        var expected = new SuperclassContainerWithNoBinding
        {
            Superclass = new UnorderedSubtype()
        };

#if TESTASYNC
        Assert.ThrowsException <AggregateException>(() => Roundtrip(expected));
#else
        Assert.ThrowsException <InvalidOperationException>(() => Roundtrip(expected));
#endif
    }