sink.prepareToWork();
    void runSinks ()    {        ListIterator iter;        if (!allSinks.isEmpty ())            iter = allSinks.listIterator ();        else            iter = allFilters.listIterator ();        // go over all the sinks        while (iter.hasNext ())        {            Operator sink;            sink = (Operator) iter.next ();            assert sink != null;            // do bunch of work            int i;            for (i = 0; i < 10; i++)            {                sink.work ();            }        }    }