code: @Override
      public String encodeAsString(long time, int sequence) {
          StringBuilder s = new StringBuilder(32);
          ByteBuffer bb = ByteBuffer.wrap(encodeAsBytes(time, sequence));
          s.append(leftPad(toHexString(bb.getLong()), 16, '0'));
          s.append(leftPad(toHexString(bb.getLong()), 16, '0'));
  
          return s.toString();
      }
docs: Return the 32 character left padded hex version of the given id. These
  can be lexicographically sorted.
  
  @param time     a time value to encode
  @param sequence a sequence value to encode
  @return 32 character left padded hex version of the given id