Object result=all_acks_received.getResultWithTimeout(timeout);
Object result=all_acks_received.getResult();
    public boolean waitForAllAcks(long timeout) throws TimeoutException {        if(missing_acks.size() == 0)            return true;        Object result=all_acks_received.getResultWithTimeout(timeout);        return result != null && result instanceof Boolean && ((Boolean)result).booleanValue();    }