How to use the crontab.CronItem function in crontab

def create_crontab(uts):
    ctab = CronTab()
    if uts.cron_type == 'h':
        if uts.cron_interval > 1:
            interval_list = [str(x) for x in range(0, 23, uts.cron_interval)]
            interval_str = ','.join(interval_list)
        else:
            interval_str = '*'
        cronline = "%s %s * * * %s runtests %s %s >/tmp/unitTestCronjob%s.out 2>&1" % (
            uts.cron_start, interval_str, os.path.join(settings.BASE_DIR, 'runmanage.sh'), uts.branch.repo.name,
            uts.branch.name, uts.id)
        logger.debug('Creating cron tab with line ' + cronline)
        item = CronItem(line=cronline + ' #' + ('%s %d' % (CRON_COMMENT, uts.id)))
        ctab.add(item)
        ctab.write()

branch.name)
        logger.debug('Creating cron tab with line ' + cronline)
        item = CronItem(line=cronline + ' #' + (CRON_COMMENT + ' %d' % branch.id))
        ctab.add(item)
        ctab.write()
    if branch.code_cron_enabled and branch.code_cron_type == 'h':
        if branch.code_cron_interval > 1:
            interval_list = [str(x) for x in range(0, 23, branch.code_cron_interval)]
            interval_str = ','.join(interval_list)
        else:
            interval_str = '*'
        cronline = "%s %s * * * %s %s %s >/var/sftmp/code_cronjob.out 2>&1" % (
            branch.code_cron_start, interval_str, os.path.join(settings.BASE_DIR, 'code_cronjob.sh'), branch.repo.name,
            branch.name)
        logger.debug('Creating cron tab with line ' + cronline)
        item = CronItem(line=cronline + ' #' + (CRON_COMMENT + ' %d' % branch.id))
        ctab.add(item)
        ctab.write()

def find_trigger(self, trigger_list):
		for job in self.crons:
			if job.get_trigger() == trigger_list:
				yield job

	def activate_triggered_jobs(self, job, state):
		for job in self.find_trigger(["toggle", job, state]):
			job.enable(not job.is_enabled())
		for job in self.find_trigger(["on", job, state]):
			job.enable(True)
		for job in self.find_trigger(["off", job, state]):
			job.enable(False)


class TCronItem(CronItem):
	"""class for extending CronItem with triggers"""

	PREFIX = "SuperCron__"
	SEPARATOR = "%"

	def __init__(self, line=None, command='', comment='', user=None, cron=None):
		super(TCronItem, self).__init__(line, command, comment, user, cron)

	def is_superjob(self):
		return self.comment.startswith(self.PREFIX)

	def get_name(self):
		if self.is_superjob():
			sep = self.comment.find(self.SEPARATOR)
			if sep == -1:
				return self.comment[len(self.PREFIX):]

def __call__(self, form, field, message=None):
        schedule = (field.data or '').strip()
        if not schedule:
            return

        try:
            CronItem().setall(schedule)
        except (KeyError, ValueError):
            message = message or self.message or field.gettext('Invalid cron')
            raise ValidationError(message)