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: time_test.go
    path of file: ./repos/wazero/internal/integration_test/vs/time
    
    the code of the file until where you have to start completion: // Package time benchmarks shows ways to implementing the platform clock more
// efficiently. As long as CGO is available, all platforms can use
// `runtime.nanotime` to more efficiently implement sys.Nanotime vs using
// time.Since or x/sys.
//
// While results would be more impressive, this doesn't show how to use
// `runtime.walltime` to avoid the double-performance vs using time.Now. The
// corresponding function only exists in darwin, so prevents this benchmark
// from running on other platforms.
package time

import (
	"testing"
	"time"
	_ "unsafe" // fo
    
func BenchmarkClock(b *testing.B) {
	b.Run("time.Now", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_ = time.Now()
		}
	})
	b.Run("ClockGettime(CLOCK_REALTIME)", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			var now unix.Timespec
			if err := unix.ClockGettime(unix.CLOCK_REALTIME, &now); err != nil {
				b.Fatal(err)
			}
		}
	})

	base := time.Now()
	b.Run("time.Since", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_ = time.Since(base)
		}
	})
	b.Run("runtime.nanotime", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			_ = nanotime()
		}
	})
	b.Run("ClockGettime(CLOCK_MONOTONIC)", func(b *testing.B) {
		for i := 0; i < b.N; i++ {
			var tick unix.Timespec
			if err := unix.ClockGettime(unix.CLOCK_MONOTONIC, &tick); err != nil {
				b.Fatal(err)
			}
		}
	})
}