public void testNullForkStack() throws Exception {
        fc1=new ForkChannel(a, "stack", "fc1");
        fc2=new ForkChannel(a, "stack", "fc2");
        MyReceiver<Integer> r1=new MyReceiver<>(), r2=new MyReceiver<>();
        fc1.setReceiver(r1); fc2.setReceiver(r2);
        a.connect(CLUSTER);
        fc1.connect("foo");
        fc2.connect("bar");

        for(int i=1; i <= 5; i++) {
            fc1.send(null, i);
            fc2.send(null, i+5);
        }

        List<Integer> l1=r1.list(), l2=r2.list();
        for(int i=0; i < 20; i++) {
            if(l1.size() == 5 && l2.size() == 5)
                break;
            Util.sleep(500);
        }

        System.out.println("r1: " + r1.list() + ", r2: " + r2.list());
        assert r1.size() == 5 && r2.size() == 5;
        for(int i=1; i <= 5; i++)
            assert r1.list().contains(i) && r2.list().contains(i+5);
    }