// if we don't have objectmeta, treat it as if all the ownerReference are newly created
		return blockingNewRefs
	}

	var ret []metav1.OwnerReference
	indexedOldRefs := indexByUID(oldMeta.GetOwnerReferences())
	for _, ref := range blockingNewRefs {
		oldRef, ok := indexedOldRefs[ref.UID]
		if !ok {
			// if ref is newly added, and it's blocking, then returns it.
			ret = append(ret, ref)
			continue
		}