'Get a specific PTR record by id.
:param service_name: the service catalog name of the linked device(s)
i.e. cloudLoadBalancers or cloudServersOpenStack
:param record_id: the id (i.e. PTR-12345) of the PTR record
:rtype: instance of :class:`RackspacePTRRecord`'

def ex_get_ptr_record(self, service_name, record_id):

    self.connection.set_context({'resource': 'record', 'id': record_id})
    response = self.connection.request(action=('/rdns/%s/%s' % (service_name, record_id))).object
    item = next(iter(response['recordsList']['records']))
    return self._to_ptr_record(data=item, link=response['link'])
