docs: public static final String characterPad(final String s, final int fieldLength, final char padChar,
        final boolean postpend) {
      final char[] chArr = s.toCharArray();
      final int sLen = chArr.length;
      if (sLen < fieldLength) {
        final char[] out = new char[fieldLength];
        final int blanks = fieldLength - sLen;
  
        if (postpend) {
          for (int i = 0; i < sLen; i++) {
            out[i] = chArr[i];
          }
          for (int i = sLen; i < fieldLength; i++) {
            out[i] = padChar;
          }
        } else { //prepend
          for (int i = 0; i < blanks; i++) {
            out[i] = padChar;
          }
          for (int i = blanks; i < fieldLength; i++) {
            out[i] = chArr[i - blanks];
          }
        }
  
        return String.valueOf(out);
      }
      return s;
    }