private Map<String, String> getDatasetUserTags(RestRequest restRequest) throws RestServiceException {
      Map<String, String> modifiedUserTags = new HashMap<>();
      if (RestUtils.isDatasetVersionQueryEnabled(restRequest.getArgs())) {
        Dataset dataset = (Dataset) restRequest.getArgs().get(RestUtils.InternalKeys.TARGET_DATASET);
        Map<String, String> userTags = dataset.getUserTags();
        if (userTags != null) {
          for (Map.Entry<String, String> entry : userTags.entrySet()) {
            modifiedUserTags.put(RestUtils.Headers.USER_META_DATA_HEADER_PREFIX + entry.getKey(), entry.getValue());
          }
        }
      }
      return modifiedUserTags;
    }
Get the user tags at dataset level.
@param restRequest the {@link RestRequest} to get dataset user tags.
@return the userTags set at dataset level.
@throws RestServiceException
ambry-frontend/src/main/java/com/github/ambry/frontend/NamedBlobPutHandler.java