protected function _cleanupCustomFields($oArticle)
    {
        $sIcon = $oArticle->oxarticles__oxicon->value;
        $sThumb = $oArticle->oxarticles__oxthumb->value;

        if ($sIcon == "nopic.jpg") {
            $oArticle->oxarticles__oxicon = new \OxidEsales\Eshop\Core\Field();
        }

        if ($sThumb == "nopic.jpg") {
            $oArticle->oxarticles__oxthumb = new \OxidEsales\Eshop\Core\Field();
        }
    }