docs: public static String encodeZeroPadding(int number, int maxNumDigits) {
          String integerString = Integer.toString(number);
          int numZeroes = maxNumDigits - integerString.length();
          StringBuffer strBuffer = new StringBuffer(numZeroes + integerString.length());
          for (int i = 0; i < numZeroes; i++) {
              strBuffer.insert(i, '0');
          }
          strBuffer.append(integerString);
          return strBuffer.toString();
      }