docs: public int parseMaxAge(String maxAgeStr) {
  
          if (maxAgeStr == null) {
              showFormatError(maxAgeStr);
              return -1;
          }
  
          maxAgeStr = maxAgeStr.toLowerCase().trim();
          String[] tokens = maxAgeStr.split(" +");
          if ((tokens.length != 2)) {
              showFormatError(maxAgeStr);
              return -1;
          }
          int number = 0;
          try {
              number = Integer.parseInt(tokens[0]);
          } catch (NumberFormatException e) {
              showFormatError(maxAgeStr);
              return -1;
          }
  
          String unit = tokens[1];
          if ("d".equals(unit) || unit.startsWith("day")) {
              return 24 * number;
          } else if ("h".equals(unit) || unit.startsWith("hour")) {
              return number;
          } else if ("w".equals(unit) || unit.startsWith("week")) {
              return 7 * 24 * number;
          } else {
              showFormatError(maxAgeStr);
              return -1;
          }
      }