@Override
  public boolean isFilesExistForPattern(PartitionId partitionId, Pattern allLogSegmentFilesPattern) {
    throw new UnsupportedOperationException("Method not supported");
  }
Returning null because this will not be used as part of CloudStorageManager Implementation.
Implementation will be added if needed.
ambry-cloud/src/main/java/com/github/ambry/cloud/CloudStorageManager.java