Type hint for websocket connection

[Paul]

What is the type hint for a websocket connection, i.e. from the example:

async def echo(websocket: ?):
    async for message in websocket:
        await websocket.send(message)

async def main():
    async with serve(echo, "localhost", 8765):
        await asyncio.Future()  # run forever

[Aymeric Augustin]

In case someone else has the same question: websockets.server.WebSocketServeProtocol