docs: static Map<String, String> parseJson(String in) {
      if (in == null) {
        return Collections.emptyMap();
      }
      String noBraces = in.replace('{', ' ').replace('}', ' ').trim();
      Map<String, String> builder = new LinkedHashMap<String, String>();
      Matcher matcher = JSON_FIELDS.matcher(noBraces);
      while (matcher.find()) {
        String key = keyMap.get(matcher.group(1));
        if (key != null) {
          builder.put(key, matcher.group(2));
        }
      }
      return builder;
    }