var ret []metav1.OwnerReference
	for _, ref := range refs {
		if ref.BlockOwnerDeletion != nil && *ref.BlockOwnerDeletion {
			ret = append(ret, ref)
		}
	}
	return ret
}

func indexByUID(refs []metav1.OwnerReference) map[types.UID]metav1.OwnerReference {
	ret := make(map[types.UID]metav1.OwnerReference)
	for _, ref := range refs {
		ret[ref.UID] = ref
	}
	return ret
}