// This timestamp is to be used instead of LastProbeTime stored in Condition. We do this
	// to avoid the problem with time skew across the cluster.
	now func() metav1.Time

	enterPartialDisruptionFunc func(nodeNum int) float32
	enterFullDisruptionFunc    func(nodeNum int) float32
	computeZoneStateFunc       func(nodeConditions []*v1.NodeCondition) (int, ZoneState)

	knownNodeSet map[string]*v1.Node