def METHOD_NAME(
    from_conf: Optional[Dict[str, Any]], default: CurrentDict
) -> CurrentDict:
    if not from_conf or not isinstance(from_conf, dict):
        return default
    # special case: if this is a valid old (i.e. not model-specific) current
    # setup, migrate it.
    if "default" not in from_conf and not (set("XYZABC") - set(from_conf.keys())):
        new_dct = deepcopy(default)
        # Because there's no case in which a machine with a more recent revision
        # than 2.1 should have a valid and edited robot config when updating
        # to this code, we should default it to 2.1 to avoid breaking other
        # robots
        new_dct["2.1"] = cast(AxisDict, from_conf)
        return new_dct
    return cast(CurrentDict, from_conf)