}
		result.UpdatedServices.Insert(nn)

		sm.merge(change.current)
		// filter out the Update event of current changes from previous changes
		// before calling unmerge() so that can skip deleting the Update events.
		change.previous.filter(change.current)
		sm.unmerge(change.previous, result.DeletedUDPClusterIPs)
	}
	// clear changes after applying them to ServicePortMap.
	sct.items = make(map[types.NamespacedName]*serviceChange)