start.php

    public function start(Request $request, AuthenticationException $authException = null)
    {
        $jwtPayload = $this->getJwtPayload($request->cookies->get('token'));
        if(isset($jwtPayload['sub'])) {
            return new Response("Don't wanna to this, really. The actual protected page should show up instead");
        }
        return new RedirectResponse($this->router->generate('login'));
    }