}

// ReplicaSetsBySizeOlder sorts a list of ReplicaSet by size in descending order, using their creation timestamp or name as a tie breaker.
// By using the creation timestamp, this sorts from old to new replica sets.
type ReplicaSetsBySizeOlder []*apps.ReplicaSet

func (o ReplicaSetsBySizeOlder) Len() int      { return len(o) }
func (o ReplicaSetsBySizeOlder) Swap(i, j int) { o[i], o[j] = o[j], o[i] }

		switch {
		case deploymentReplicasToAdd > 0:
			sort.Sort(controller.ReplicaSetsBySizeNewer(allRSs))
			scalingOperation = "up"

		case deploymentReplicasToAdd < 0:
			sort.Sort(controller.ReplicaSetsBySizeOlder(allRSs))
			scalingOperation = "down"
		}

		// Iterate over all active replica sets and estimate proportions for each of them.
		// The absolute value of deploymentReplicasAdded should never exceed the absolute