docs: public URLNormalizer decodeUnreservedCharacters() {
          if (url.contains("%")) {
              StringBuffer sb = new StringBuffer();
              Matcher m = PATTERN_PERCENT_ENCODED_CHAR.matcher(url);
              try {
                  while (m.find()) {
                      String enc = m.group(1).toUpperCase();
                      if (isEncodedUnreservedCharacter(enc)) {
                          m.appendReplacement(sb, URLDecoder.decode(
                                  enc, StandardCharsets.UTF_8.toString()));
                      }
                  }
              } catch (UnsupportedEncodingException e) {
                  logger.debug("UTF-8 is not supported by your system. "
                          + "URL will remain unchanged:" + url, e);
              }
              url = m.appendTail(sb).toString();
          }
          return this;
      }