docs: @Override
      public void checkRepositoryStatus() throws IOException, RequestFailureException {
          HttpURLConnection connection = createHeadConnection("/assets");
          testResponseCode(connection);
          Map<String, List<String>> results = connection.getHeaderFields();
          if (results == null) {
              throw new RequestFailureException(connection.getResponseCode(), "No header returned, this does not look like a valid repository", connection.getURL(), null);
          }
          List<String> count = results.get("count");
          if (count == null) {
              throw new RequestFailureException(connection.getResponseCode(), "No count returned, this does not look like a valid repository", connection.getURL(), null);
          }
      }