source.registerPush();
    private void enqueue (Object o)    {        queue.addLast (o);        		totalItemsPushed++;        // overflow at 50 chars in the queue        if (queue.size () > 100 && !declaredFull)        {                source.addFullChannel (this);            declaredFull = true;        }        // make sure that the channel isn't overflowing        //if (queue.size () == maxSize) System.out.print ("*");        assert queue.size () <= maxSize || maxSize == -1:            "Expecting queue.size () <= maxSize || maxSize == -1,\n" +            "   but queue.size()==" + queue.size() + " and maxSize==" +             maxSize;		        if (passThrough) {	    sink.prepareToWork();	    sink.work ();	}    }