code: static List<String> parsePattern(String pattern) {
      List<String> parameters = new ArrayList<>(4);
      Matcher matcher = PARAM_REGEX.matcher(pattern);
      while (matcher.find()) {
        parameters.add(matcher.group(1));
      }
      return parameters;
    }
docs: Get the list of parameters from the given pattern.
  
  @param pattern the given pattern
  @return the parameters list, or empty if no parameter found from the given pattern