func TestOverlaySetup(t *testing.T) {
	graphtest.GetDriver(t, driverName)
}
This avoids creating a new driver for each test if all tests are run
Make sure to put new tests between TestOverlaySetup and TestOverlayTeardown
package overlay
import (
	"io/ioutil"
	"os"
	"testing"
	graphdriver "github.com/containers/storage/drivers"
	"github.com/containers/storage/drivers/graphtest"
	"github.com/containers/storage/pkg/archive"
	"github.com/containers/storage/pkg/reexec"
)
const driverName = "overlay"
func init() {
	untar = archive.UntarUncompressed
	graphdriver.ApplyUncompressedLayer = archive.ApplyUncompressedLayer
	reexec.Init()
}
func skipIfNaive(t *testing.T) {
	td, err := ioutil.TempDir("", "naive-check-")
	if err != nil {
		t.Fatalf("Failed to create temp dir: %v", err)
	}
	defer os.RemoveAll(td)
	if err := doesSupportNativeDiff(td, ""); err != nil {
		t.Skipf("Cannot run test with naive diff")
	}
}