gen.defineOutput("out1");
gen.defineOutput("out2");
gen.connect("in1", "op1").connect("op1.a", "op2").connect("op2", "out1");
gen.connect("op1.b", "out2");
FlowGraph graph = gen.toGraph();
getPlanner().insertCheckpoints(graph);
assertThat(FlowGraphUtil.collectBoundaries(graph),
not(gen.getAsSet("in1", "op1", "op2", "out1", "out2")));
Set<FlowElement> a = FlowGraphUtil.getSucceedingBoundaries(gen.output("op1.a"));