@Override
  public void registerLiveInstanceChangeListener(LiveInstanceChangeListener liveInstanceChangeListener) {
    // no op
  }
Constructor for {@link MockVcrClusterSpectator} object.
@param cloudDataNodeList list of cloud {@link MockDataNodeId}s in instance config of {@link MockVcrClusterSpectator}.
ambry-test-utils/src/main/java/com/github/ambry/clustermap/MockVcrClusterSpectator.java