// test messageThrottleStage
ClusterEvent event = new ClusterEvent("testEvent");
event.addAttribute("helixmanager", manager);
Pipeline dataRefresh = new Pipeline();
dataRefresh.addStage(new ReadClusterDataStage());
runPipeline(event, dataRefresh);
runStage(event, new ResourceComputationStage());
MessageSelectionStageOutput msgSelectOutput = new MessageSelectionStageOutput();
Message msg3 =