@Override
  public PartitionId getRandomWritablePartition(String partitionClass, List<PartitionId> partitionsToExclude) {
    lastRequestedPartitionClasses.add(partitionClass);
    if (!partitionsUnavailable) {
      return partitionSelectionHelper.getRandomWritablePartition(partitionClass, partitionsToExclude);
    }
    return null;
  }
Return if ssl ports are enabled in this cluster.
ambry-test-utils/src/main/java/com/github/ambry/clustermap/MockClusterMap.java