@Override
      public Map<String, Map<String, ProcessingComponent>> getTasks() {
        ManualTask mt = new ManualTask();
        mt.messages = Lists.newArrayList("My New Message");

        ProcessingComponent pc = new ProcessingComponent();
        pc.name = "NIMBUS_MESSAGE";
        pc.preTasks = Lists.newArrayList(mt);

        return Collections.singletonMap("STORM", Collections.singletonMap("NIMBUS", pc));
      }
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