code: public static CronTriggerBuilder cronTriggerBuilder(String cronExpression) throws ParseException {
  
      CronExpression.validateExpression(cronExpression);
      return new CronTriggerBuilder(cronExpression);
    }
docs: Create a CronScheduleBuilder with the given cron-expression.
  
  @param cronExpression the cron expression to base the schedule on.
  @return the new CronScheduleBuilder
  @throws ParseException
  @see CronExpression