docs: public static @Nullable String get(@NotNull ServletRequest request, @NotNull String param, @Nullable String defaultValue) {
      String value = request.getParameter(param);
      if (value != null) {
        // convert encoding to UTF-8 if not form encoding parameter is set
        if (!hasFormEncodingParam(request)) {
          value = convertISO88591toUTF8(value);
        }
        return value;
      }
      else {
        return defaultValue;
      }
    }