access to previous success cron from CronJob instance

I needed to access to previous success cron from my CronJob instance, to get previous success start and end date. This issue shall provide such access:

    class MyCronJob(CronJobBase):
        RUN_EVERY_MINS = 15 # every 15 minutes

        schedule = Schedule(run_every_mins=RUN_EVERY_MINS)
        code = 'my_app.my_cron_job'    # a unique code

        def do(self):
            prev_success_cron = self.get_prev_success_cron()
            if prev_success_cron is not None:
                # access to all fields of models.CronJobLog here