@Retention(value=RUNTIME)
@Target(value=METHOD)
public @interface CronSchedule
CronSchedule - Optional cron schedule for workflow. If a cron schedule is specified, the workflow
will run as a cron based on the schedule. The scheduling will be based on UTC time. Schedule for
next run only happen after the current run is completed/failed/timeout. If a RetryPolicy is also
supplied, and the workflow failed or timeout, the workflow will be retried based on the retry
policy. While the workflow is retrying, it won't schedule its next run. If next schedule is due
while workflow is running (or retrying), then it will skip that schedule. Cron workflow will not
stop until it is terminated or canceled.