public function RemoveRestrictedItems()
    {
        // since this is a tcmsrecord list, we need to collect all valid ids, and the reload the list with them
        $aValidIds = array();
        $this->GoToStart();
        while ($oItem = &$this->Next()) {
            if ($oItem->IsPublic()) {
                $aValidIds[] = MySqlLegacySupport::getInstance()->real_escape_string($oItem->id);
            }
        }

        $query = 'SELECT `shop_shipping_type`.*
                  FROM `shop_shipping_type`
                 WHERE ';
        if (count($aValidIds) > 0) {
            $query .= " `shop_shipping_type`.`id` IN ('".implode("','", $aValidIds)."') ";
        } else {
            $query .= ' 1 = 0 ';
        }
        $query .= ' ORDER BY `shop_shipping_type`.`position`';
        $this->Load($query);
    }