Device component:

    for dev_uuid, sub_device in new_sub_devices.items():

        ctrl_uuid = get_device_controller_uuid(sub_device)

        LOGGER.info('dev_uuid={:s}, ctrl_uuid={:s}'.format(str(dev_uuid), str(ctrl_uuid)))

        if dev_uuid == device_uuid: continue # current device has no dependencies

        if ctrl_uuid is None: continue # sub_device has no controller

        if ctrl_uuid == device_uuid: continue # current device has no dependencies

        predecesors = graph.setdefault(dev_uuid, set())

        LOGGER.info('dev_uuid={:s} predecesors={:s}'.format(str(dev_uuid), str(predecesors)))

        predecesors.add(ctrl_uuid)

        LOGGER.info('graph={:s}'.format(str(graph)))

    LOGGER.info('final graph={:s}'.format(str(graph)))

    try:

        ts = TopologicalSorter(graph)

        sorted_sub_device_uuids.extend(list(ts.static_order()))

        sorted_sub_device_uuids.remove(device_uuid)

    except CycleError:

        MSG = 'Topological sort failed due to cycle among sub-devices({:s}), graph({:s})'

        msg = MSG.format(str(new_sub_devices), str(graph))