code: @Test public void testSingleStagePlan(){
    RoleCommandOrder.initialize();
    RoleCommandOrder rco=new RoleCommandOrder();
    RoleGraph rg=new RoleGraph(rco);
    String hostname="dummy";
    Stage stage=StageUtils.getATestStage(1,1,hostname);
    rg.build(stage);
    List<Stage> outStages=rg.getStages();
    for (  Stage s : outStages) {
      System.out.println(s.toString());
    }
    assertEquals(1,outStages.size());
    assertEquals(stage.getExecutionCommands(hostname),outStages.get(0).getExecutionCommands(hostname));
  }
  