def Subclasses(cls, sort_by=None, reverse=False):
        l = list()
        for attr, value in get_all_attributes(cls):
            try:
                if issubclass(value, Constant):
                    l.append((attr, value))
            except:
                pass
        if sort_by is None:
            sort_by = "__creation_index__"
        l = list(
            sorted(l, key=lambda x: getattr(x[1], sort_by), reverse=reverse))
        return l