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: bench_test.go
    path of file: ./repos/wazero/internal/sysfs
    
    the code of the file until where you have to start completion: package sysfs

import (
	"io"
	"io/fs"
	"os"
	"path"
	"testing"
	"time"

	"github.com/tetratelabs/wazero/experimental/sys"
)

func BenchmarkFsFileUtimesNs(b *testing.B) {
	f, errno := OpenOSFile(path.Join(b.TempDir(), "file"), sys.O_CREAT, 0)
	if errno != 0 {
		b.Fatal(errno)
	}
	defer f.Close()

	atim := int64(123*time.Second + 4*time.Microsecond)
	mtim := atim

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		if errno := f.Utimens(atim, mtim); errno != 0 {
			b.Fatal(errno)
		}
	}
}

func BenchmarkFsFileRead(b *testing.B) {
	dirFS := os.DirFS("testdata")
	embedFS, err := fs.Sub(testdata, "testdata")
	if err != nil {
		b.Fatal(err)
	}

	benches := []struct {
		name  string
		fs    fs.FS
		pread bool
	}{
		{name: "os.DirFS Read", fs: dirFS, pread: false},
		{name: "os.DirFS Pread", fs: dirFS, pread: true},
		{name: "embed.api.FS Read", fs: embedFS, pread: false},
		{name: "embed.api.FS Pread", fs: embedFS, pread: true},
	}

	buf := make([]byte, 3)

	for _, bc := range benches {
		bc := bc

		b.Run(bc.name, func(b *testing.B) {
			name := "wazero.txt"
			f, errno := OpenFSFile(bc.fs, name, sy
    
func BenchmarkFsFileRead(b *testing.B) {
	dirFS := os.DirFS("testdata")
	embedFS, err := fs.Sub(testdata, "testdata")
	if err != nil {
		b.Fatal(err)
	}

	benches := []struct {
		name  string
		fs    fs.FS
		pread bool
	}{
		{name: "os.DirFS Read", fs: dirFS, pread: false},
		{name: "os.DirFS Pread", fs: dirFS, pread: true},
		{name: "embed.api.FS Read", fs: embedFS, pread: false},
		{name: "embed.api.FS Pread", fs: embedFS, pread: true},
	}

	buf := make([]byte, 3)

	for _, bc := range benches {
		bc := bc

		b.Run(bc.name, func(b *testing.B) {
			name := "wazero.txt"
			f, errno := OpenFSFile(bc.fs, name, sys.O_RDONLY, 0)
			if errno != 0 {
				b.Fatal(errno)
			}
			defer f.Close()

			b.ResetTimer()
			for i := 0; i < b.N; i++ {
				b.StopTimer()

				var n int
				var errno sys.Errno

				// Reset the read position back to the beginning of the file.
				if _, errno = f.Seek(0, io.SeekStart); errno != 0 {
					b.Fatal(errno)
				}

				b.StartTimer()
				if bc.pread {
					n, errno = f.Pread(buf, 3)
				} else {
					n, errno = f.Read(buf)
				}
				b.StopTimer()

				if errno != 0 {
					b.Fatal(errno)
				} else if bufLen := len(buf); n < bufLen {
					b.Fatalf("nread %d less than capacity %d", n, bufLen)
				}
			}
		})
	}
}