pmKey80 := endpointsliceutil.NewPortMapKey([]discovery.EndpointPort{{Port: &p80}})

	spCacheEfficient := NewEndpointPortCache()
	spCacheEfficient.Set(pmKey80, EfficiencyInfo{Endpoints: 45, Slices: 1})
	spCacheEfficient.Set(pmKey80443, EfficiencyInfo{Endpoints: 35, Slices: 1})

	spCacheInefficient := NewEndpointPortCache()
	spCacheInefficient.Set(pmKey80, EfficiencyInfo{Endpoints: 12, Slices: 5})

// total numbers of desired endpoints and the efficiency of EndpointSlice
// endpoints distribution.
type EfficiencyInfo struct {
	Endpoints int
	Slices    int
}

// NewEndpointPortCache initializes and returns a new EndpointPortCache.
func NewEndpointPortCache() *EndpointPortCache {
	return &EndpointPortCache{
		items: map[endpointsliceutil.PortMapKey]EfficiencyInfo{},
	}
}

	}

	// Build data structures for existing state.
	existingSlicesByKey := endpointSlicesByKey(existingSlices)

	// Determine changes necessary for each group of slices by port map.
	epMetrics := metrics.NewEndpointPortCache()
	totals := totalsByAction{}
	slices := slicesByAction{}

	for portKey, desiredEndpoints := range d.endpointsByKey {
		numEndpoints := len(desiredEndpoints)
		pmSlices, pmTotals := r.reconcileByPortMapping(