protected function permissionDenied($user, $uri, &$response)
    {
        $_SESSION['GlobalMessage']['error'] = 'You do not have permission to access: ' . $uri;

        $log = Log::create(Log::TYPE_PERMISSION, 'user', 'Unauthorised access attempt.');
        $log->setUser($user);
        $log->setLink($uri);
        $log->save();

        $response = new RedirectResponse($response);
        $response->setHeader('Location', $this->config->get('site.full_admin_url'));
        $response->flush();
    }