}

    static class OldBase extends OldSuperInternal {
        void anotherPublicMethod() {}

        OldBase returnTypeOverridenMethod() { return null }
    }

    static class OldSub extends OldBase {
        OldSub returnTypeOverridenMethod() { return null }
    }

    static class NewSuperInternal {}

    static class NewBase extends NewSuperInternal {}

    static class NewSub extends NewBase {}