public function onLogoutSuccess(Request $request)
    {
        phpCAS::setDebug($this->cas->getDebug());
        phpCAS::setVerbose($this->cas->isVerbose());
        if (!phpCAS::isInitialized()) {
            phpCAS::client(
                $this->cas->getVersion(),
                $this->cas->getHostname(),
                $this->cas->getPort(),
                $this->cas->getUrl()
            );
        }
        phpCAS::setLang($this->cas->getLanguage());

        if ($this->cas->isRedirectingAfterLogout()) {
            $uri = $this->router->generate(
                $this->cas->getRouteLogout(),
                [],
                UrlGeneratorInterface::ABSOLUTE_URL
            );
            phpCAS::logoutWithRedirectService($uri);
        } else {
            //simple logout
            phpCAS::logout();
        }
    }