protected function _refresh()
    {
        $where = $this->_getWhereQuery();
        $row = $this->_getTable()->fetchRow($where);

        if (null === $row) {
            // require_once 'Zend/Db/Table/Row/Exception.php';
            throw new Zend_Db_Table_Row_Exception('Cannot refresh row as parent is missing');
        }

        $this->_data = $row->toArray();
        $this->_cleanData = $this->_data;
        $this->_modifiedFields = array();
    }