code: public void setCronExpression (@Nonnull final String expression) throws ParseException
    {
      final CronExpression newExp = new CronExpression (expression);
  
      setCronExpression (newExp);
    }
docs: Sets the cron expression for the calendar to a new value
  
  @param expression
  the new string value to build a cron expression from
  @throws ParseException
  if the string expression cannot be parsed