public function get($oid, $preserveKeys = false) {
        if ($this->cache() && ( $rtn = $this->getCache()->load($oid) ) !== null) {
            return $rtn;
        }

        try {
            $this->_lastResult = $this->_session->get($oid, $preserveKeys);
        } catch (Exception $exc) {
            $this->close();
            throw new Exception("Erro '{$this->_session->getError()}' with execute GET OID ({$oid}): " . $exc->getMessage());
        }

        if ($this->_lastResult === false) {
            $this->close();
            throw new Exception('Could not perform walk for OID ' . $oid);
        }

        return $this->getCache()->save($oid, $this->parseSnmpValue($this->_lastResult));
    }