def update_ptr_record(self, device, record, domain_name, data=None,
            ttl=None, comment=None):
        """
        Updates a PTR record with the supplied values.
        """
        device_type = self._resolve_device_type(device)
        href, svc_name = self._get_ptr_details(device, device_type)
        try:
            rec_id = record.id
        except __HOLE__:
            rec_id = record
        rec = {"name": domain_name,
              "id": rec_id,
              "type": "PTR",
              "data": data,
            }
        if ttl is not None:
            # Minimum TTL is 300 seconds
            rec["ttl"] = max(300, ttl)
        if comment is not None:
            # Maximum comment length is 160 chars
            rec["comment"] = comment[:160]
        body = {"recordsList": {
                    "records": [rec]},
                "link": {
                    "content": "",
                    "href": href,
                    "rel": svc_name,
                }}
        uri = "/rdns"
        try:
            resp, resp_body = self._async_call(uri, body=body, method="PUT",
                    has_response=False, error_class=exc.PTRRecordUpdateFailed)
        except exc.EndpointNotFound as e:
            raise exc.InvalidPTRRecord("The record domain/IP address "
                    "information is not valid for this device.")
        return resp_body.get("status") == "COMPLETED"
dataset/ETHPy150Open rackspace/pyrax/pyrax/clouddns.py/CloudDNSManager.update_ptr_record