Symfony: Right way to get default target URL from session http://goo.gl/SNq3Tr

LoginSuccessHandler.php

<?php

namespace AppBundle\Security\Authentication\Handler;

use Symfony\Component\HttpFoundation\RedirectResponse;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
use Symfony\Component\Security\Http\Authentication\AuthenticationSuccessHandlerInterface;

class LoginSuccessHandler implements AuthenticationSuccessHandlerInterface
{
    private $container;
    private $session;
    private $router;
    private $tokenStorage;
    
    public function __construct(ContainerInterface $container)
    {
        $this->container = $container;
        $this->session = $container->get('session');
        $this->router = $container->get('router');

        if ($this->container->has('security.token_storage')) {
            $this->tokenStorage = $this->container->get('security.token_storage');
        } else {
            $this->tokenStorage = $this->container->get('security.context');
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function onAuthenticationSuccess(TokenInterface $token)
    {
        // ....
        
        $defaultTargetPath = sprintf('_security.%s.target_path', $this->tokenStorage->getToken()->getProviderKey());

        if ($this->session->has($defaultTargetPath)) {
            $url = $this->session->get($defaultTargetPath);
        }
        
        // ....
        
        return new RedirectResponse($url);
    }
}