// item in this list nevertheless constitutes user error.
		setNames := []string{}
		for _, s := range sets {
			setNames = append(setNames, s.Name)
		}
		utilruntime.HandleError(
			fmt.Errorf(
				"user error: more than one StatefulSet is selecting pods with labels: %+v. Sets: %v",
				pod.Labels, setNames))
	}
	return sets
}