@classmethod
def active_unique_routes_at_stop(cls, session, stop_id, agency_id=None,
    date=None, route_name_filter=False):
    """
        to filter active routes, just provide a date to the above unique_routes_at_stop method
        """
    ret_val = []
    routes = cls.unique_routes_at_stop(session, stop_id, agency_id, date,
        route_name_filter)
    for r in routes:
        if r.is_active(date):
            ret_val.append(r)
    return ret_val
