code: public static String getHistoryResourceURI(String uri, ServletRequest req) {
  
          String histUri = uri;
          if (CmsHistoryResourceHandler.isHistoryRequest(req)) {
              String version = req.getParameter(CmsHistoryResourceHandler.PARAM_VERSION);
              histUri = CmsRequestUtil.appendParameter(uri, CmsHistoryResourceHandler.PARAM_VERSION, version);
          }
          return histUri;
      }
docs: Appends the <code>version</code> parameter to the URI if needed.<p>
  
  @param uri the resource URI
  @param req the current request
  
  @return the same URI, with additional parameters in case of a historical request