docs: public static Map<String, List<String>> getResponseHeaders(String stringUrl,
        boolean followRedirects) throws IOException {
      URL url = new URL(stringUrl);
      HttpURLConnection conn = (HttpURLConnection) url.openConnection();
      conn.setInstanceFollowRedirects(followRedirects);
      
      InputStream is = conn.getInputStream();
      if ("gzip".equals(conn.getContentEncoding())) {
         is = new GZIPInputStream(is);
      }
  
      Map<String, List<String>> headers = new LinkedHashMap<String, List<String>>(conn.getHeaderFields());
      headers.put("X-Content", Arrays.asList(MyStreamUtils.readContent(is)));
      headers.put("X-URL", Arrays.asList(conn.getURL().toString()));
      headers.put("X-Status", Arrays.asList(String.valueOf(conn.getResponseCode())));
      
      return headers;
    }