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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def kube_cronjob_next_schedule_time(self, metric, scraper_config):
 """ Time until the next schedule """

        # Used as a service check so that one can be alerted if the cronjob's next schedule is in the past
        check_basename = scraper_config['namespace'] + '.cronjob.on_schedule_check'
        curr_time = int(time.time())
        for sample in metric.samples:
            on_schedule = int(sample[self.SAMPLE_VALUE]) - curr_time
            tags = [
                self._format_tag(label_name, label_value, scraper_config)
                for label_name, label_value in iteritems(sample[self.SAMPLE_LABELS])
            ]
            tags += scraper_config['custom_tags']
            if on_schedule < 0:
                message = "The service check scheduled at {} is {} seconds late".format(
                    time.strftime('%Y-%m-%d %H:%M:%S', time.gmtime(int(sample[self.SAMPLE_VALUE]))), on_schedule
                )
                self.service_check(check_basename, self.CRITICAL, tags=tags, message=message)
            else:
                self.service_check(check_basename, self.OK, tags=tags)