code: func (cronJobStrategy) PrepareForUpdate(ctx context.Context, obj, old runtime.Object) {
  	newCronJob := obj.(*batch.CronJob)
  	oldCronJob := old.(*batch.CronJob)
  	newCronJob.Status = oldCronJob.Status
  
  	pod.DropDisabledTemplateFields(&newCronJob.Spec.JobTemplate.Spec.Template, &oldCronJob.Spec.JobTemplate.Spec.Template)
  }
docs: // PrepareForUpdate clears fields that are not allowed to be set by end users on update.