log.error("UnicastTest.sendMessages(): receiver is null, cannot send messages");
System.err.println("UnicastTest.sendMessages(): receiver is null, cannot send messages");
    void sendMessages() throws Exception {        long num_msgs=getNumberOfMessages();        Address receiver=getReceiver();        Message msg;        Value val=new Value(1);        if(receiver == null) {            log.error("UnicastTest.sendMessages(): receiver is null, cannot send messages");            return;        }        System.out.println("sending " + num_msgs + " messages to " + receiver);        msg=new Message(receiver, null, new StartData(num_msgs));        channel.send(msg);        for(int i=1; i <= num_msgs; i++) {            val=new Value(i);            msg=new Message(receiver, null, val);            if(i % 100 == 0)                System.out.println("-- sent " + i);            channel.send(msg);            if(sleep_time > 0)                Util.sleep(sleep_time, busy_sleep);        }        System.out.println("done sending " + num_msgs + " to " + receiver);    }