private function _getObject($id, $revision = null)
    {
        if ($revision === null) {
            $select = Statement::get(
                'GET_CURRENT_OBJECT',
                [
                    '@collection' => $this->_name,
                    '@id' => $this->_connector->quote($id)
                ]
            );
            $record = $this->_connector->query($select)->fetch();
            if ($record) {
                return json_decode($record['obj']);
            }
        }
        return null;
    }