code: protected String getRelativePath(String ancestor, String rootPath) {
  
          String result = rootPath.substring(ancestor.length());
          result = CmsStringUtil.joinPaths("/", result, "/");
          return result;
      }
docs: Computes the relative path given an ancestor folder path.<p>
  
  @param ancestor the ancestor folder
  @param rootPath the path for which the relative path should be computed
  
  @return the relative path