@client.on(events.NewMessage(incoming=True))
async def say_brb(event):
    global turned_on, already_messaged_users
    sender = (await event.get_sender())
    if ((not event.is_private) or (not turned_on) or (sender.id in already_messaged_users)):
        return
    already_messaged_users.add(sender.id)
    (await event.reply(sleeping_txt))
@client.on(events.NewMessage(incoming=True))
async def say_brb(event):
    global turned_on, already_messaged_users
    sender = (await event.get_sender())
    if ((not event.is_private) or (not turned_on) or (sender.id in already_messaged_users)):
        return
    already_messaged_users.add(sender.id)
    (await event.reply(sleeping_txt))