protected Pair<String, String> assertClientOK(final OAuthRegisteredService service,
                                                  final boolean refreshToken) throws Throwable {
        return assertClientOK(service, refreshToken, null);
    }
This is {@link AbstractOAuth20Tests}.

@author Misagh Moayyed
@since 5.0.0
support/cas-server-support-oauth/src/test/java/org/apereo/cas/AbstractOAuth20Tests.java