if (lst.isEmpty()) {  return; }
    protected void react() throws IOException {        while (true) {            ArrayList lst = readReply();            if (((ReplyLine)lst.get(0)).status.startsWith("6"))                handleEvent(lst);            else {                Waiter w;                synchronized (waiters) {                    w = (Waiter) waiters.removeFirst();                }                w.setResponse(lst);            }        }    }