Cogroup cog1 = f.cogroup(in1, core.empty(Ex2.class));
Cogroup cog2 = f.cogroup(in1, core.empty(Ex2.class));
core.stop(cog1.r2);
core.stop(cog2.r2);
FoldFlowFactory fff = new FoldFlowFactory();
Confluent<Ex1> con1 = core.confluent(cog1.r1, cog2.r1);
Simple fold = fff.simple(con1);
out1.add(fold.out);
}