class WebSocketTransport(AsyncIOEventEmitter, Transport):
    ...
    async def run(self) -> None:
        ...

        try:
            self._connection = await websockets.connect(self.ws_endpoint, **options)
        except Exception as exc:
            self.emit("close")
            self.on_error_future.set_exception(exc)
       ...

class PlaywrightContextManager:
    ...
    async def __aenter__(self) -> AsyncPlaywright:
        ...
        done, pending = await asyncio.wait(
            {
                self._connection._transport.on_error_future,
                self._connection.wait_for_object_with_known_name("Playwright"),
            },
            return_when=asyncio.FIRST_COMPLETED,
        )
        obj = next(iter(done)).result()
        playwright = AsyncPlaywright(obj)
        ...