public function getBackOfficeLanguage()
    {
        $currentLanguage = $this->session->get(self::KEY_LOCALE);

        if (!$currentLanguage) {
            $currentLanguage = $this->defaultLocale;
            $token = $this->tokenStorage->getToken();
            if ($token && ($user = $token->getUser()) instanceof UserInterface) {
                if (null !== $user->getLanguage()) {
                    $currentLanguage = $user->getLanguage();
                }
                $this->setBackOfficeLanguage($currentLanguage);
            }
        }

        return $currentLanguage;

    }