func TempFile() string {
	return randFile(os.TempDir(), "", "")
}
TempFile returns the path to a temporary file that does not exits.
Tempfile is essentially a random filename generator.
package tests
import (
	"os"
	"path/filepath"
	"strconv"
	"sync"
	"testing"
	"time"
)
var (
	rand uint32
	mu   sync.Mutex
)