@Override
      public List<Grouping> getGroups(Direction direction) {

        Grouping g = new Grouping();

        OrderService orderService = new OrderService();
        orderService.serviceName = "STORM";
        orderService.components = singletonList("NIMBUS");

        g.name = "GROUP1";
        g.title = "Nimbus Group";
        g.services.add(orderService);

        return Lists.newArrayList(g);
      }
Tests that advanced {@link Grouping} instances like {@link StopGrouping}
work with rolling upgrade packs.

@throws Exception
ambari-server/src/test/java/org/apache/ambari/server/stack/upgrade/orchestrate/UpgradeHelperTest.java