def get_emoji_subgroups(group):
    """Return the subgroups of this group, in order, or None
    if the group is not recognized."""
    _load_emoji_group_data()
    subgroups = []
    subgroup = None
    for _, g, sg, _ in sorted(_emoji_group_data.values()):
        if g == group:
            if sg != subgroup:
                subgroup = sg
                subgroups.append(subgroup)
    return subgroups if subgroups else None