def METHOD_NAME(self, request, obj):
    """
    If id was changed, always returns to the list (prevent 404).
    Otherwise, behave as usual.
    """
    if self.oldid is not None:
        msg = _('Difficulty id {old} was changed to {new} successfully.').format(
            old=self.oldid, new=obj.pk)
        self.message_user(request, msg)
        return self.response_post_save_change(request, obj)
    return super().METHOD_NAME(request, obj)