code: public function ipGetReverse($id, $ip)
      {
          if (!$id)
              throw new BadMethodCallException('Missing parameter $id.');
          if (!$ip)
              throw new BadMethodCallException('Missing parameter $ip.');
          return json_decode($this->getIpProperties($id, $ip))->reverse;
      }
docs: Return ip reverse (hostname)
  
  @param string $id
  @param string $ip
  @return string reverse
  @throws \Ovh\Common\Exception\BadMethodCallException