public function itemsProcFunc(&$params)
    {
        // if this tt_content element is inline element of mask
        if ($params["row"]["colPos"] == $this->colPos) {
            // only allow mask nested element column
            $params["items"] = array(
                array(
                    \TYPO3\CMS\Extbase\Utility\LocalizationUtility::translate('mask_content_colpos', 'mask'),
                    $this->colPos,
                    null,
                    null
                )
            );
        } else { // if it is not inline tt_content element
            // and if other itemsProcFunc from other extension was available (e.g. gridelements),
            // then call it now and let it render the items
            if (!empty($params["config"]["m_itemsProcFunc"])) {
                \TYPO3\CMS\Core\Utility\GeneralUtility::callUserFunction($params["config"]["m_itemsProcFunc"], $params,
                    $this);
            }
        }
    }