docs: protected String normalizeRfsPrefix(String rfsPrefix) {
  
          String result = insertContextStrings(rfsPrefix);
          if (!isValidURL(result)) {
              result = CmsFileUtil.normalizePath(result, '/');
          }
          if (CmsResource.isFolder(result)) {
              // ensure prefix does NOT end with a folder '/'
              result = result.substring(0, result.length() - 1);
          }
          return result;
      }