DEFAULT_NO_PS, // configuration null, no preset Subject
        DEFAULT_WITH_PS, // configuration null, but super.getSubject() returns non-null
        WITH_CONFIG // configuration provided via StaticJAASConfiguration
    }

    private JAASAuthenticator buildAuthenticator(SubjectVariant variant) {
        switch (variant) {
        case DEFAULT_WITH_PS: {
            JAASAuthenticator a = new JAASAuthenticator();