'Returns the coordinator broker for a consumer group.
GroupCoordinatorNotAvailableError will be raised if the coordinator
does not currently exist for the group.
GroupLoadInProgressError is raised if the coordinator is available
but is still loading offsets from the internal topic'

def _get_coordinator_for_group(self, group):

    resp = self.send_consumer_metadata_request(group)
    kafka.errors.check_error(resp)
    return BrokerMetadata(resp.nodeId, resp.host, resp.port, None)
