k := make([]string, n)
	for i := 0; i < len(k); i++ {
		k[i] = strconv.Itoa(i)
	}
	b.ResetTimer()
	a := make(map[string]int)
	for i := 0; i < b.N; i++ {
		a[k[i&(n-1)]] = i
	}
}

func benchmarkMapOperatorAssignStr(b *testing.B, n int) {
	k := make([]string, n)
	for i := 0; i < len(k); i++ {
		k[i] = strconv.Itoa(i)
	}
	b.ResetTimer()
	a := make(map[string]string)

}

func benchmarkSendFile(b *testing.B, proto string) {
	for i := 0; i <= 10; i++ {
		size := 1 << (i + 10)
		bench := sendFileBench{
			proto:     proto,
			chunkSize: size,
		}
		b.Run(strconv.Itoa(size), bench.benchSendFile)
	}
}

type sendFileBench struct {
	proto     string
	chunkSize int
}

func (bench sendFileBench) benchSendFile(b *testing.B) {
	fileSize := b.N * bench.chunkSize

func tempFile(ctx context.Context, dir, prefix string, perm fs.FileMode) (f *os.File, err error) {
	for i := 0; i < 10000; i++ {
		name := filepath.Join(dir, prefix+strconv.Itoa(rand.Intn(1000000000))+".tmp")
		f, err = os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, perm)
		if os.IsExist(err) {
			if ctx.Err() != nil {
				return nil, ctx.Err()
			}
			continue
		}
		break