code: func (autoscalerStrategy) PrepareForUpdate(ctx context.Context, obj, old runtime.Object) {
  	newHPA := obj.(*autoscaling.HorizontalPodAutoscaler)
  	oldHPA := old.(*autoscaling.HorizontalPodAutoscaler)
  	// Update is not allowed to set status
  	newHPA.Status = oldHPA.Status
  }
docs: // PrepareForUpdate clears fields that are not allowed to be set by end users on update.