@Override
  public void onBlobCreated(String blobId, BlobProperties blobProperties, Account account, Container container,
      NotificationBlobType notificationBlobType) {
    // ignore
  }
A mock notification system that helps to identify when blobs
get replicated. This class is not thread safe
ambry-test-utils/src/main/java/com/github/ambry/server/MockNotificationSystem.java