'Send a PING to the remote client, it should reply with a PONG which
will be sent to the handle_websocket_pong callback in your handler.'

def send_websocket_ping(self, data=''):

    if isinstance(data, type(u'')):
        data = data.encode(u'utf-8')
    frame = create_frame(True, PING, data)
    with self.cf_lock:
        self.control_frames.append(ReadOnlyFileBuffer(frame))
