public function onDisplayTool(OpenAdministrationToolEvent $event)
    {
        $content = $this->templating->render(
            'ClarolineCoreBundle:administration:users.html.twig', [
                // todo : put it in the async load of form
                'parameters' => $this->parametersSerializer->serialize(),
                'profile' => $this->profileSerializer->serialize(),
                'platformRoles' => $this->finder->search('Claroline\CoreBundle\Entity\Role', [
                    'filters' => ['type' => Role::PLATFORM_ROLE],
                ]),
            ]
        );

        $event->setResponse(new Response($content));
        $event->stopPropagation();
    }