async lock error about pyee HOT 1 CLOSED

import pyee
import asyncio
from asyncio.locks import Lock


class Demo(pyee.AsyncIOEventEmitter):
    def __init__(self):
        super().__init__()
        self._lock = Lock()

    async def get_seq(self):
        async with self._lock:
            return 1

    async def send(self):
        seq = await self.get_seq()
        self.emit('event_test')


class LockTest(pyee.AsyncIOEventEmitter):
    def __init__(self):
        super().__init__()

        self._demo = Demo()
        self._demo.on('event_test', self._on_event_test)

    async def _on_event_test(self):
        print('_on_event_test')

    async def send(self):
        await self._demo.send()


async def run():
    test = LockTest()
    await test.send()


if __name__ == '__main__':
    asyncio.run(run())