private void addReplicasToDisk(DataNodeConfigSource dataNodeConfigSource, String host, String disk, String partition) {
    // Add replicas to property store
    DataNodeConfig dataNodeConfig = getDataNodeConfig(dataNodeConfigSource, host);
    setDataNodeConfig(dataNodeConfig, disk, partition, dataNodeConfigSource);
  }
Case when no instance is down and all instances are present in ideal state or external view
@param helixManager
@param dataNodeConfigSource
@return
ambry-clustermap/src/test/java/com/github/ambry/clustermap/PropertyStoreCleanUpTaskTest.java