docs: public URLNormalizer addDirectoryTrailingSlash() {
          String urlRoot = HttpURL.getRoot(url);
          String path = toURL().getPath();
          String urlRootAndPath = urlRoot + path;
  
          String name = StringUtils.substringAfterLast(path, "/");
          if (StringUtils.isNotBlank(name) && !name.contains(".")) {
              String newPath = path + "/";
              String newUrlRootAndPath = urlRoot + newPath;
              url = StringUtils.replaceOnce(
                      url, urlRootAndPath, newUrlRootAndPath);
          }
          return this;
      }