public function logout(UserInterface $user = null, $everywhere = false)
    {
        try {
            $user = $this->sentinel->logout($user, $everywhere);
        } catch (Exception $e) {
            return $this->returnException($e);
        }

        if (!$this->sentinel->check()) {
            $message = $this->translate('user_logout', 'You have been logged out');
            return new SuccessReply($message);
        }

        $message = $this->translate('generic_problem', 'There was a problem. Please contact a site administrator.');
        return new FailureReply($message);
    }