gen.defineOperator("op1", "in", "out");
gen.defineOperator("op2", "in", "out");
gen.defineOutput("out");
gen.connect("in", "op1").connect("op1", "op2").connect("op2", "out");
FlowGraph graph = gen.toGraph();
getPlanner().reduceIdentities(graph);
assertThat(FlowGraphUtil.collectElements(graph),
is(gen.getAsSet("in", "op1", "op2", "out")));
assertThat(succ(gen.get("in")), is(gen.get("op1")));