public function doHydrateList(array $list, $parentKey = null)
    {
        $retVal = parent::doHydrateList($list, $parentKey);

        if('Id' === $parentKey)
        {
            if($retVal->count() > 0)
            {
                return $retVal->get(0);
            }
            return null;
        }
        return $retVal;
    }