我想自动回复新的私人信息，我还没有一个对话之前。但我的代码给出了一个错误，我不能找出什么解决方案。
这是我尝试过的：

from telethon import TelegramClient, events
from telethon import functions, types
from time import sleep

api_id = 123456
api_hash = 'enterownapihash'

msg = 'Sorry, I am unavailable right now.'

client = TelegramClient('automessage', api_id, api_hash, sequential_updates=True)
@client.on(events.NewMessage(incoming=True, blacklist_chats=True))

async def setup():
    users = set()
    async for dialog in client.iter_dialogs():
        if dialog.is_user:
            users.add(dialog.id)

async def handler(event):
    if event.is_private and event.sender_id not in users:
        await event.respond(msg)

这是我得到的错误：

Unhandled exception on setup
Traceback (most recent call last):
  File "C:\Users\user\AppData\Local\Programs\Python\Python310\lib\site-packages\telethon\client\updates.py", line 520, in _dispatch_update
    await callback(event)
TypeError: setup() takes 0 positional arguments but 1 was given

现在尝试了这个：

from telethon import TelegramClient, events
from telethon import functions, types
from time import sleep

api_id = 123456
api_hash = 'enterownapihash'

msg = 'Sorry, I am unavailable right now.'

client = TelegramClient('automessage', api_id, api_hash, sequential_updates=True)

async def setup():
    global users
    users = set()
    async for dialog in client.iter_dialogs():
        if dialog.is_user and not dialog.entity.bot:
            users.add(dialog.id)

@client.on(events.NewMessage(incoming=True))
async def handler(event):
    if event.is_private and event.sender_id not in users:
        await event.respond(msg)

client.start()
client.run_until_disconnected()

每当我的帐户收到消息时，我都会收到此错误：

Unhandled exception on handler
Traceback (most recent call last):
  File "C:\Users\user\AppData\Local\Programs\Python\Python310\lib\site-packages\telethon\client\updates.py", line 520, in _dispatch_update
    await callback(event)
  File "C:\Users\user\Desktop\Scripts\CODING\telethon\AutoRespond.py", line 27, in handler
    if event.is_private and event.sender_id not in users:
NameError: name 'users' is not defined

解决这个问题的方法是什么？提前感谢！