log.error("Must submit 'done' (press 'd') before mcasting new message");
System.err.println("Must submit 'done' (press 'd') before mcasting new message");
    public void mcast(int num) throws IOException {        if(!done_submitted) {            log.error("Must submit 'done' (press 'd') before mcasting new message");            return;        }        for(int i=0; i < num; i++) {            Util.sleep(100);            System.out.println("Casting message #" + i);            disp.castMessage(null,                    i,                    new Message(null, null, "Number #" + i),                    coll);        }        done_submitted=false;    }