protected void describe() {
ExOperatorFactory f = new ExOperatorFactory();
CoreOperatorFactory core = new CoreOperatorFactory();
Update update0 = f.update(in1, 1);
Update update1 = f.update(core.checkpoint(update0.out), 2);
Cogroup cog1 = f.cogroup(update1.out, core.empty(Ex2.class));
core.stop(cog1.r2);
Cogroup cog2 = f.cogroup(update1.out, core.empty(Ex2.class));
core.stop(cog2.r2);
out1.add(cog1.r1);
out2.add(cog2.r1);