@Override
  public VcrClusterSpectator getVcrClusterSpectator(CloudConfig cloudConfig, ClusterMapConfig clusterMapConfig) {
    return null;
  }
{@link StaticVcrClusterAgentsFactory} to generate VCR Cluster for static partition assignment.
ambry-cloud/src/main/java/com/github/ambry/cloud/StaticVcrClusterAgentsFactory.java