ScheduleCalendarSpec to a CronExpressions?

does temporal have a helper method to convert a ScheduleCalendarSpec to a CronExpressions ? our current users prefer to use cron notation to create schedules. So we want to show that back to users.

Right now if i use the List Schedule API it returns the ScheduleCalendarSpec and the CronExpression is set to nil. This make it difficult to show what cron was inputed.

Thanks,
Derek