'Get the destination for result by task id.
Returns:
Tuple[str, str]: tuple of ``(reply_to, correlation_id)``.'

def destination_for(self, task_id, request):

    try:
        request = (request or current_task.request)
    except AttributeError:
        raise RuntimeError(u'RPC    backend    missing    task    request    for    {0!r}'.format(task_id))
    return (request.reply_to, (request.correlation_id or task_id))
