code: static private StringBuilder formatLineId(StringBuilder buffer, int value) {
          char[] chars = new char[4];
          for (int i = 3; i >= 0; i--) {
              chars[i] = (char) HEX_BYTES[(value % 16) & 0xF];
              value >>= 4;
          }
          return buffer.append(chars);
      }
docs: Format the input value as a four digit hex number, padding with zeros.
  
  @param buffer
  @param value
  @return StringBuilder