如何限制tornado websocket消息大小

我在tornado中编写了一个websocket服务器 on_message

这是我的代码,用于获取长度仅小于128字节的消息,但它似乎不起作用。

class ClientWebSocketConnectionHandler(tornado.websocket.WebSocketHandler):

    def open(self):
        print "Connection is opened"

    def on_message(self, message):
        print message

    def on_close(self):
        print "closed"

handlers = [(r'/', ClientWebSocketConnectionHandler)]
tornado.web.Application.__init__(self, handlers)
TheShieldsWebSocket = MainApplication()
server =tornado.httpserver.HTTPServer(TheShieldsWebSocket,max_body_size=128)
server.listen(8080)