code: static void checkNegativeLS(
          long posixTime,
          PlainTimestamp ts
      ) {
  
          LeapSeconds ls = LeapSeconds.getInstance();
  
          if (
              ls.supportsNegativeLS()
              && (ls.strip(ls.enhance(posixTime)) > posixTime)
          ) {
              throw new ChronoException(
                  "Illegal local timestamp due to "
                  + "negative leap second: " + ts);
          }
  
      }
docs: <p>Pr&uuml;ft, ob eine negative Schaltsekunde vorliegt. </p>
  
  @param   posixTime   UNIX-time in seconds
  @param   ts          local timestamp used for error message
  @throws  ChronoException if a negative leap second is touched