public function realWalk($oid, $suffixAsKey = false) {
        try {
            $return = $this->_lastResult = $this->_session->walk($oid, $suffixAsKey);
        } catch (Exception $exc) {
            $this->close();
            throw new Exception("Erro '{$this->_session->getError()}' with execute WALK OID ({$oid}): " . $exc->getMessage());
        }

        return $return;
    }