code: private String LPad(String inStr, int maxLen) {
          if (inStr.length() >= maxLen) return inStr.toUpperCase();
          String zeroes = PADCHARS.substring(0, maxLen - inStr.length());
          String retVal = zeroes + inStr;
          return retVal.toUpperCase();
      }
docs: /*
  LPad Return a String, left padded with '0's as specified
  by the caller.