public function Grant(Action $action, $onObject)
    {
        if ($onObject instanceof Page)
        {
            return $this->GrantOnPage($onObject);
        }
        if ($onObject instanceof Content)
        {
            return $this->GrantOnContent($onObject, $action);
        }
        else
        {
            throw new \LogicException('Frontend access check not implemented for type '. get_class($onObject));
        }
        return GrantResult::Allowed();
    }