docs: private String getOAuthAuthString(HttpRequest req)
              throws OAuthException, IOException, URISyntaxException {
          RealmOAuthConsumer consumer = getConsumer();
          OAuthAccessor accessor = new OAuthAccessor(consumer);
  
          String method = req.getMethod().name();
          URI uri = req.getURI();
  
          OAuthMessage msg = accessor.newRequestMessage(method, uri.toString(), null);
          return msg.getAuthorizationHeader(consumer.getRealm());
      }