@Override
  public List<ClusterParticipant> getClusterParticipants() {
    return Collections.emptyList();
  }
Create and return a {@link CompositeClusterManager}.
@return the constructed {@link CompositeClusterManager}.
@throws Exception if constructing the underlying {@link StaticClusterManager} or the {@link HelixClusterManager}
throws an Exception.
ambry-clustermap/src/main/java/com/github/ambry/clustermap/CompositeClusterAgentsFactory.java