How to use the billiard.five.range function in billiard

def _avail_index(self):
        assert len(self._pool) < self._processes
        indices = set(p.index for p in self._pool)
        return next(i for i in range(self._processes) if i not in indices)

def grow(self, n=1):
        for i in range(n):
            self._processes += 1
            if self._putlock:
                self._putlock.grow()
        self.on_grow(n)

# The worker may have published a result before being terminated,
        # but we have no way to accurately tell if it did.  So we wait for
        # _lost_worker_timeout seconds before we mark the job with
        # WorkerLostError.
        for job in [job for job in list(self._cache.values())
                    if not job.ready() and job._worker_lost]:
            now = now or monotonic()
            lost_time, lost_ret = job._worker_lost
            if now - lost_time > job._lost_worker_timeout:
                self.mark_as_worker_lost(job, lost_ret)

        if shutdown and not len(self._pool):
            raise WorkersJoined()

        cleaned, exitcodes = {}, {}
        for i in reversed(range(len(self._pool))):
            worker = self._pool[i]
            exitcode = worker.exitcode
            popen = worker._popen
            if popen is None or exitcode is not None:
                # worker exited
                debug('Supervisor: cleaning up worker %d', i)
                if popen is not None:
                    worker.join()
                debug('Supervisor: worked %d joined', i)
                cleaned[worker.pid] = worker
                exitcodes[worker.pid] = exitcode
                if exitcode not in (EX_OK, EX_RECYCLE) and \
                        not getattr(worker, '_controlled_termination', False):
                    error(
                        'Process %r pid:%r exited with %r',
                        worker.name, worker.pid, human_status(exitcode),

def close_open_fds(keep=None):  # noqa
        keep = [maybe_fileno(f)
                for f in (keep or []) if maybe_fileno(f) is not None]
        for fd in reversed(range(get_fdmax(default=2048))):
            if fd not in keep:
                try:
                    os.close(fd)
                except OSError as exc:
                    if exc.errno != errno.EBADF:
                        raise

def _ack(self, i, time_accepted, pid, *args):
        start = i * self._chunksize
        stop = min((i + 1) * self._chunksize, self._length)
        for j in range(start, stop):
            self._accepted[j] = True
            self._worker_pid[j] = pid
            self._time_accepted[j] = time_accepted
        if self.ready():
            self._cache.pop(self._job, None)

def _ensure_messages_consumed(self, completed):
        """ Returns true if all messages sent out have been received and
        consumed within a reasonable amount of time """

        if not self.on_ready_counter:
            return False

        for retry in range(GUARANTEE_MESSAGE_CONSUMPTION_RETRY_LIMIT):
            if self.on_ready_counter.value >= completed:
                debug('ensured messages consumed after %d retries', retry)
                return True
            time.sleep(GUARANTEE_MESSAGE_CONSUMPTION_RETRY_INTERVAL)
        warning('could not ensure all messages were consumed prior to '
                'exiting')
        return False

def _repopulate_pool(self, exitcodes):
        """Bring the number of pool processes up to the specified number,
        for use after reaping workers which have exited.
        """
        for i in range(self._processes - len(self._pool)):
            if self._state != RUN:
                return
            try:
                if exitcodes and exitcodes[i] not in (EX_OK, EX_RECYCLE):
                    self.restart_state.step()
            except IndexError:
                self.restart_state.step()
            self._create_worker_process(self._avail_index())
            debug('added worker')