How to use the huey.contrib.sqlitedb.Schedule function in huey

def schedule(self, *columns):
        return (Schedule
                .select(*columns)
                .where(Schedule.queue == self.name)
                .order_by(Schedule.timestamp))

def schedule(self, *columns):
        return (Schedule
                .select(*columns)
                .where(Schedule.queue == self.name)
                .order_by(Schedule.timestamp))

def read_schedule(self, ts):
        tasks = (self
                 .schedule(Schedule.id, Schedule.data)
                 .where(Schedule.timestamp <= ts)
                 .tuples())
        id_list, data = [], []
        for task_id, task_data in tasks:
            id_list.append(task_id)
            data.append(task_data)
        if id_list:
            (Schedule
             .delete()
             .where(Schedule.id << id_list)
             .execute())
        return data

def add_to_schedule(self, data, ts):
        Schedule.create(data=data, timestamp=ts, queue=self.name)

def schedule(self, *columns):
        return (Schedule
                .select(*columns)
                .where(Schedule.queue == self.name)
                .order_by(Schedule.timestamp))

def read_schedule(self, ts):
        tasks = (self
                 .schedule(Schedule.id, Schedule.data)
                 .where(Schedule.timestamp <= ts)
                 .tuples())
        id_list, data = [], []
        for task_id, task_data in tasks:
            id_list.append(task_id)
            data.append(task_data)
        if id_list:
            (Schedule
             .delete()
             .where(Schedule.id << id_list)
             .execute())
        return data