gRPC サーバーからすべてのクライアントにイベントをブロードキャストするにはどうすればよいですか?

<code class="python"># Server-side code
class UpdaterServer:
    def post_update(self, update):
        with self.condition:
            self.updates.append(update)
            self.condition.notify_all()

    def GetUpdates(self, req, context):
        while self.updates[req.last_received_update + 1:] == []:
            self.condition.wait()
        new_updates = self.updates[req.last_received_update + 1:]
        response = GetUpdatesResponse()
        for update in new_updates:
            response.updates.add().CopyFrom(update)
        response.update_index = req.last_received_update + len(new_updates)
        return response

# Client-side code
request = GetUpdatesRequest()
request.last_received_update = -1
while True:
    try:
        response = stub.GetUpdates(request, timeout=60*10)
        handle_updates(response.updates)
        request.last_received_update = response.update_index
    except grpc.FutureTimeoutError:
        pass</code>