func newDesiredCalc() *desiredCalc {
	return &desiredCalc{
		portsByKey:          map[addrTypePortMapKey][]discovery.EndpointPort{},
		endpointsByKey:      map[addrTypePortMapKey]endpointsliceutil.EndpointSet{},
		numDesiredEndpoints: 0,
	}
}

// desiredCalc helps calculate desired endpoints and ports.
type desiredCalc struct {
	portsByKey          map[addrTypePortMapKey][]discovery.EndpointPort

	for portKey, desiredEndpoints := range d.endpointsByKey {
		numEndpoints := len(desiredEndpoints)
		pmSlices, pmTotals := r.reconcileByPortMapping(
			endpoints, existingSlicesByKey[portKey], desiredEndpoints, d.portsByKey[portKey], portKey.addressType())

		slices.append(pmSlices)
		totals.add(pmTotals)

		epMetrics.Set(endpointsliceutil.PortMapKey(portKey), metrics.EfficiencyInfo{
			Endpoints: numEndpoints,