You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: store_test.go
    path of file: ./repos/sharingan/grpc-server/v1.33.2/xds/internal/client/load
    
    the code of the file until where you have to start completion: /*
 *
 * Copyright 2020 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package load

import (
	"fmt"
	"sort"
	"sync"
	"testing"

	"github.com/google/go-cmp/cmp"
	"github.com/google/go-cmp/cmp/cmpopts"
)

var (
	dropCategories = []string{"drop_for_real", "drop_for_fun"}
	localities     = []string{"locality-A", "locality-B"}
	errTest        = fmt.Errorf("test error")
)

// rpcData wraps the rpc counts and load data to be pushed to the store.
type rpcData struct {
	start, success, failure int
	serverData              map[string]float64 // Will be reported with successful RPCs.
}

// TestDrops spawns a bunch of goroutines which report drop data. After the
// goroutines have exited, the test dumps the stats from the Store and makes
// sure they are as expected.
func TestDrops(t *testing.T) {
	var (
		drops = map[string]int{
			dropCategories[0]: 30,
			dropCategories[1]: 40,
		}
		wantStoreData = &Data{
			TotalDrops: 70,
			Drops: map[string]uint64{
				dropCategories[0]: 30,
				dropCategories[1]: 40,
			},
		}
	)

	ls := perClusterStore{}
	var wg sync.WaitGroup
	for category, count := range drops {
		for i := 0; i < count; i++ {
			wg.Add(1)
			go func(c string
    
func TestLocalityStats(t *testing.T) {
	var (
		localityData = map[string]rpcData{
			localities[0]: {
				start:      40,
				success:    20,
				failure:    10,
				serverData: map[string]float64{"net": 1, "disk": 2, "cpu": 3, "mem": 4},
			},
			localities[1]: {
				start:      80,
				success:    40,
				failure:    20,
				serverData: map[string]float64{"net": 1, "disk": 2, "cpu": 3, "mem": 4},
			},
		}
		wantStoreData = &Data{
			LocalityStats: map[string]LocalityData{
				localities[0]: {
					RequestStats: RequestData{Succeeded: 20, Errored: 10, InProgress: 10},
					LoadStats: map[string]ServerLoadData{
						"net":  {Count: 20, Sum: 20},
						"disk": {Count: 20, Sum: 40},
						"cpu":  {Count: 20, Sum: 60},
						"mem":  {Count: 20, Sum: 80},
					},
				},
				localities[1]: {
					RequestStats: RequestData{Succeeded: 40, Errored: 20, InProgress: 20},
					LoadStats: map[string]ServerLoadData{
						"net":  {Count: 40, Sum: 40},
						"disk": {Count: 40, Sum: 80},
						"cpu":  {Count: 40, Sum: 120},
						"mem":  {Count: 40, Sum: 160},
					},
				},
			},
		}
	)

	ls := perClusterStore{}
	var wg sync.WaitGroup
	for locality, data := range localityData {
		wg.Add(data.start)
		for i := 0; i < data.start; i++ {
			go func(l string) {
				ls.CallStarted(l)
				wg.Done()
			}(locality)
		}
		// The calls to callStarted() need to happen before the other calls are
		// made. Hence the wait here.
		wg.Wait()

		wg.Add(data.success)
		for i := 0; i < data.success; i++ {
			go func(l string, serverData map[string]float64) {
				ls.CallFinished(l, nil)
				for n, d := range serverData {
					ls.CallServerLoad(l, n, d)
				}
				wg.Done()
			}(locality, data.serverData)
		}
		wg.Add(data.failure)
		for i := 0; i < data.failure; i++ {
			go func(l string) {
				ls.CallFinished(l, errTest)
				wg.Done()
			}(locality)
		}
		wg.Wait()
	}

	gotStoreData := ls.stats()
	if diff := cmp.Diff(wantStoreData, gotStoreData, cmpopts.EquateEmpty(), cmpopts.IgnoreFields(Data{}, "ReportInterval")); diff != "" {
		t.Errorf("store.stats() returned unexpected diff (-want +got):\n%s", diff)
	}
}