/**
    * Checks that the board is currently active (and can be viewed by the visitor)
    * or throws an exception.
    *
    * @param string $action
    */
    protected function _assertBoardActive($action)
    {
        $options = XenForo_Application::get('options');
        if (!$options->boardActive && !XenForo_Visitor::getInstance()->get('is_admin'))
        {
            throw $this->responseException($this->responseMessage($options->boardInactiveMessage), 503);
        }
    }