code: @VisibleForTesting
    void initializeHelixManager() {
      this.multiManager = new GobblinHelixMultiManager(
          this.config, new Function<Void, MessageHandlerFactory>() {
            @Override
            public MessageHandlerFactory apply(Void aVoid) {
              return GobblinClusterManager.this.getUserDefinedMessageHandlerFactory();
            }
          }, this.eventBus, stopStatus) ;
      this.multiManager.addLeadershipChangeAwareComponent(this);
    }
docs: In separate controller mode, one controller will manage manager's HA, the other will handle the job dispatching and
  work unit assignment.