Plan plan = env.createProgramPlan("Test union on new java-api");
OptimizedPlan oPlan = compileNoStats(plan);
NepheleJobGraphGenerator jobGen = new NepheleJobGraphGenerator();
// Compile plan to verify that no error is thrown
jobGen.compileJobGraph(oPlan);
oPlan.accept(new Visitor<PlanNode>() {
@Override
public boolean preVisit(PlanNode visitable) {