void registerMockStateChangeListeners() {
    registerPartitionStateChangeListener(StateModelListenerType.ReplicationManagerListener,
        mockReplicationManagerListener);
    if (mockStatsManagerListener != null) {
      registerPartitionStateChangeListener(StateModelListenerType.StatsManagerListener, mockStatsManagerListener);
    }
  }
Re-register state change listeners in {@link HelixParticipant} to replace original one with mock state change
listener. This is to help with special test cases.
ambry-clustermap/src/test/java/com/github/ambry/clustermap/MockHelixParticipant.java