// code should be sync with Symfony\Component\Security\Core\Authorization\Voter\ExpressionVoter
    private function getVariables(GuardEvent $event)
    {
        $variables = array(
            'subject' => $event->getSubject(),
            // needed for the is_granted expression function
            'auth_checker' => $this->authenticationChecker,
            // needed for the is_* expression function
            'trust_resolver' => $this->trustResolver,
        );

        $token = $this->tokenStorage->getToken();
        if (null !== $token) {
            if (null !== $this->roleHierarchy) {
                $roles = $this->roleHierarchy->getReachableRoles($token->getRoles());
            } else {
                $roles = $token->getRoles();
            }

            $variables['token'] = $token;
            $variables['user']  = $token->getUser();
            $variables['roles'] = array_map(function ($role) {
                return $role->getRole();
            }, $roles);
        }

        return $variables;
    }