static boolean isAuthorizedGrantTypeForService(final String grantType,
                                                   final OAuthRegisteredService registeredService) {
        return isAuthorizedGrantTypeForService(grantType, registeredService, false);
    }
Is authorized grant type for service?

@param grantType         the grant type
@param registeredService the registered service
@return true/false
support/cas-server-support-oauth-api/src/main/java/org/apereo/cas/support/oauth/web/OAuth20RequestParameterResolver.java