public JSONObject toJson() {
    JSONObject jsonObject = new JSONObject().put(BLOB_NAME_KEY, blobName);
    if (expirationTimeMs != Utils.Infinite_Time) {
      jsonObject.put(EXPIRATION_TIME_MS_KEY, expirationTimeMs);
    }
    jsonObject.put(BLOB_SIZE_KEY, blobSize);
    jsonObject.put(MODIFIED_TIME_MS_KEY, modifiedTimeMs);
    jsonObject.put(IS_DIRECTORY_KEY, isDirectory);
    return jsonObject;
  }
@return this list entry as a {@link JSONObject}.
ambry-api/src/main/java/com/github/ambry/frontend/NamedBlobListEntry.java