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: btrfs_test.go
    path of file: ./repos/moby/daemon/graphdriver/btrfs
    
    the code of the file until where you have to start completion: //go:build linux

package btrfs // import "github.com/docker/docker/daemon/graphdriver/btrfs"

import (
	"os"
	"path"
	"testing"

	"github.com/docker/docker/daemon/graphdriver/graphtest"
)

// This avoids creating a new driver for each test if all tests are run
// Make sure to put new tests between TestBtrfsSetup and TestBtrfsTeardown
func TestBtrfsSe
    
func TestBtrfsSubvolDelete(t *testing.T) {
	d := graphtest.GetDriver(t, "btrfs")
	if err := d.CreateReadWrite("test", "", nil); err != nil {
		t.Fatal(err)
	}
	defer graphtest.PutDriver(t)

	dir, err := d.Get("test", "")
	if err != nil {
		t.Fatal(err)
	}
	defer d.Put("test")

	if err := subvolCreate(dir, "subvoltest"); err != nil {
		t.Fatal(err)
	}

	if _, err := os.Stat(path.Join(dir, "subvoltest")); err != nil {
		t.Fatal(err)
	}

	if err := d.Remove("test"); err != nil {
		t.Fatal(err)
	}

	if _, err := os.Stat(path.Join(dir, "subvoltest")); !os.IsNotExist(err) {
		t.Fatalf("expected not exist error on nested subvol, got: %v", err)
	}
}