docs: public static Map<String, String> parseQueryString(String s) {
          Map<String, String> ht = new HashMap<String, String>();
          StringTokenizer st = new StringTokenizer(s, "&");
          while (st.hasMoreTokens()) {
              String pair = st.nextToken();
              int pos = pair.indexOf('=');
              if (pos == -1) {
                  ht.put(pair.toLowerCase(), "");
              } else {
                  ht.put(pair.substring(0, pos).toLowerCase(),
                         pair.substring(pos + 1));
              }
          }
          return ht;
      }