func Setup(t *testing.T) *storage.Client {
	if testProject == "" || testBucket == "" {
		t.Skip("TESTPROJECT, and TESTBUCKET EnvVars must be set to perform integration test")
	}

	gcsctx := &cloudstorage.CloudStoreContext{
		LogggingContext: "testing-config",
		TokenSource:     cloudstorage.GCEDefaultOAuthToken,
		Project:         testProject,
		Bucket:          testBucket,
	}

	// Create http client with Google context auth
	googleClient, err := cloudstorage.NewGoogleClient(gcsctx)
	if err != nil {
		t.Errorf("Failed to create Google Client: %v\n", err)
	}

	gsc, err := storage.NewClient(context.Background(), option.WithHTTPClient(googleClient.Client()))
	if err != nil {
		t.Errorf("Error creating Google cloud storage client. project:%s gs://%s/ err:%v\n",
			gcsctx.Project, gcsctx.Bucket, err)

	}
	if gsc == nil {
		t.Errorf("storage Client returned is nil!")
	}
	return gsc
}

// getInstalledTLS returns the TLS certificate and key stored on Google Cloud Storage for the
// instance defined in d.Conf.
//
// If either the TLS keypair doesn't exist, the error is os.ErrNotExist.
func (d *Deployer) getInstalledTLS() (certPEM, keyPEM []byte, err error) {
	ctx := context.Background()
	stoClient, err := cloudstorage.NewClient(ctx, option.WithHTTPClient(d.Client))
	if err != nil {
		return nil, nil, fmt.Errorf("error creating Cloud Storage client to fetch TLS cert & key from new instance: %v", err)
	}
	getFile := func(name string) ([]byte, error) {
		sr, err := stoClient.Bucket(d.Conf.bucketBase()).Object(path.Join(configDir, name)).NewReader(ctx)
		if err == cloudstorage.ErrObjectNotExist {
			return nil, os.ErrNotExist
		}
		if err != nil {
			return nil, err
		}
		defer sr.Close()
		return ioutil.ReadAll(sr)
	}
	var grp syncutil.Group
	grp.Go(func() (err error) {
		certPEM, err = getFile(certFilename())
		return
	})
	grp.Go(func() (err error) {
		keyPEM, err = getFile(keyFilename())
		return
	})
	err = grp.Err()
	return
}

func newTestClient(rt http.RoundTripper) *Client {
	t, err := NewClient(context.Background(), testProjectID, option.WithHTTPClient(&http.Client{Transport: rt}))
	if err != nil {
		panic(err)
	}
	return t
}

// NewClient creates a new PubSub client.
func NewClient(ctx context.Context, projectID string, opts ...option.ClientOption) (*Client, error) {
	var o []option.ClientOption
	// Environment variables for gcloud emulator:
	// https://option.google.com/sdk/gcloud/reference/beta/emulators/pubsub/
	if addr := os.Getenv("PUBSUB_EMULATOR_HOST"); addr != "" {
		o = []option.ClientOption{
			option.WithEndpoint("http://" + addr + "/"),
			option.WithHTTPClient(http.DefaultClient),
		}
	} else {
		o = []option.ClientOption{
			option.WithEndpoint(prodAddr),
			option.WithScopes(raw.PubsubScope, raw.CloudPlatformScope),
			option.WithUserAgent(userAgent),
		}
	}
	o = append(o, opts...)
	httpClient, endpoint, err := transport.NewHTTPClient(ctx, o...)
	if err != nil {
		return nil, fmt.Errorf("dialing: %v", err)
	}

	s, err := newPubSubService(httpClient, endpoint)
	if err != nil {
		return nil, fmt.Errorf("constructing pubsub client: %v", err)
	}

	c := &Client{
		projectID: projectID,
		s:         s,
	}

	return c, nil
}

// Test that BucketIterator's Next method correctly terminates if there is
// nothing to iterate over.
func TestEmptyBucketIterator(t *testing.T) {
	hClient, close := newTestServer(func(w http.ResponseWriter, r *http.Request) {
		io.Copy(ioutil.Discard, r.Body)
		fmt.Fprintf(w, "{}")
	})
	defer close()
	ctx := context.Background()
	client, err := NewClient(ctx, option.WithHTTPClient(hClient))
	if err != nil {
		t.Fatal(err)
	}
	it := client.Buckets(ctx, "project")
	c := make(chan error, 1)
	go func() {
		_, err := it.Next()
		c <- err
	}()
	select {
	case err := <-c:
		if err != iterator.Done {
			t.Errorf("got %v, want Done", err)
		}
	case <-time.After(50 * time.Millisecond):
		t.Error("timed out")
	}
}

func TestEncryption(t *testing.T) {
	ctx := context.Background()
	ft := &fakeTransport{}
	hc := &http.Client{Transport: ft}
	client, err := NewClient(ctx, option.WithHTTPClient(hc))
	if err != nil {
		t.Fatalf("error when creating client: %v", err)
	}
	obj := client.Bucket("bucketname").Object("filename1")
	key := []byte("secret-key-that-is-32-bytes-long")
	wc := obj.Key(key).NewWriter(ctx)
	// TODO(jba): use something other than fakeTransport, which always returns error.
	wc.Write([]byte("hello world"))
	wc.Close()
	if got, want := ft.gotReq.Header.Get("x-goog-encryption-algorithm"), "AES256"; got != want {
		t.Errorf("algorithm: got %q, want %q", got, want)
	}
	gotKey, err := base64.StdEncoding.DecodeString(ft.gotReq.Header.Get("x-goog-encryption-key"))
	if err != nil {
		t.Fatalf("decoding key: %v", err)
	}
	if !reflect.DeepEqual(gotKey, key) {
		t.Errorf("key: got %v, want %v", gotKey, key)
	}
	wantHash := sha256.Sum256(key)
	gotHash, err := base64.StdEncoding.DecodeString(ft.gotReq.Header.Get("x-goog-encryption-key-sha256"))
	if err != nil {
		t.Fatalf("decoding hash: %v", err)
	}
	if !reflect.DeepEqual(gotHash, wantHash[:]) { // wantHash is an array
		t.Errorf("hash: got\n%v, want\n%v", gotHash, wantHash)
	}
}

func upload(srcPath string) {
	if !*flagUpload {
		return
	}
	destName := strings.Replace(filepath.Base(srcPath), "camlistore", "camlistore-"+releaseDate.Format(fileDateFormat), 1)
	versionedTarball := "monthly/" + destName

	log.Printf("Uploading %s/%s ...", bucket, versionedTarball)

	ts, err := tokenSource(bucket)
	if err != nil {
		log.Fatal(err)
	}
	ctx := context.Background()
	stoClient, err := storage.NewClient(ctx, option.WithTokenSource(ts), option.WithHTTPClient(oauth2.NewClient(ctx, ts)))
	if err != nil {
		log.Fatal(err)
	}
	w := stoClient.Bucket(bucket).Object(versionedTarball).NewWriter(ctx)
	w.ACL = publicACL(project)
	w.CacheControl = "no-cache" // TODO: remove for non-tip releases? set expirations?
	contentType := "application/x-gtar"
	if strings.HasSuffix(versionedTarball, ".zip") {
		contentType = "application/zip"
	}
	w.ContentType = contentType
	csw := sha256.New()
	mw := io.MultiWriter(w, csw)

	src, err := os.Open(srcPath)
	if err != nil {
		log.Fatal(err)
	}
	defer src.Close()

	if _, err := io.Copy(mw, src); err != nil {
		log.Fatalf("io.Copy: %v", err)
	}
	if err := w.Close(); err != nil {
		log.Fatalf("closing GCS storage writer: %v", err)
	}
	log.Printf("Uploaded monthly tarball to %s", versionedTarball)

	// And upload the corresponding checksum
	checkSumFile := versionedTarball + ".sha256"
	sum := fmt.Sprintf("%x", csw.Sum(nil))
	w = stoClient.Bucket(bucket).Object(checkSumFile).NewWriter(ctx)
	w.ACL = publicACL(project)
	w.CacheControl = "no-cache" // TODO: remove for non-tip releases? set expirations?
	w.ContentType = "text/plain"
	if _, err := io.Copy(w, strings.NewReader(sum)); err != nil {
		log.Fatalf("error uploading checksum %v: %v", checkSumFile, err)
	}
	if err := w.Close(); err != nil {
		log.Fatalf("closing GCS storage writer: %v", err)
	}
	log.Printf("Uploaded monthly tarball checksum to %s", checkSumFile)
}

// uploadReleaseTarball uploads the generated tarball of binaries in
// camlistore-release/VERSION/camlistoreVERSION-REV-CONTENTS.EXT. It then makes a copy in
// the same bucket and path, as camlistoreVERSION-CONTENTS.EXT.
func uploadReleaseTarball() {
	proj := "camlistore-website"
	bucket := "camlistore-release"
	tarball := *flagVersion + "/" + filepath.Base(releaseTarball)
	versionedTarball := strings.Replace(tarball, "camlistore"+*flagVersion, "camlistore"+*flagVersion+"-"+rev(), 1)

	log.Printf("Uploading %s/%s ...", bucket, versionedTarball)

	ts, err := tokenSource(bucket)
	if err != nil {
		log.Fatal(err)
	}
	ctx := context.Background()
	stoClient, err := storage.NewClient(ctx, option.WithTokenSource(ts), option.WithHTTPClient(oauth2.NewClient(ctx, ts)))
	if err != nil {
		log.Fatal(err)
	}
	w := stoClient.Bucket(bucket).Object(versionedTarball).NewWriter(ctx)
	w.ACL = publicACL(proj)
	w.CacheControl = "no-cache" // TODO: remove for non-tip releases? set expirations?
	contentType := "application/x-gtar"
	if *buildOS == "windows" {
		contentType = "application/zip"
	}
	w.ContentType = contentType

	src, err := os.Open(releaseTarball)
	if err != nil {
		log.Fatal(err)
	}
	defer src.Close()

	if _, err := io.Copy(w, src); err != nil {
		log.Fatalf("io.Copy: %v", err)
	}
	if err := w.Close(); err != nil {
		log.Fatalf("closing GCS storage writer: %v", err)
	}
	log.Printf("Uploaded tarball to %s", versionedTarball)
	if !isWIP() {
		log.Printf("Copying tarball to %s/%s ...", bucket, tarball)
		dest := stoClient.Bucket(bucket).Object(tarball)
		if _, err := stoClient.Bucket(bucket).Object(versionedTarball).CopyTo(
			ctx,
			dest,
			&storage.ObjectAttrs{
				ACL:         publicACL(proj),
				ContentType: contentType,
			}); err != nil {
			log.Fatalf("Error uploading %v: %v", tarball, err)
		}
		log.Printf("Uploaded tarball to %s", tarball)
	}
}

func TestTranslateURL(t *testing.T) {
	// The translate API has all inputs in the URL.
	// Make sure we generate the right one.
	ctx := context.Background()
	ft := &fakeTransport{}
	c, err := NewClient(ctx, option.WithHTTPClient(&http.Client{Transport: ft}))
	if err != nil {
		t.Fatal(err)
	}
	for _, test := range []struct {
		target language.Tag
		inputs []string
		opts   *Options
		want   url.Values
	}{
		{language.Spanish, []string{"text"}, nil, url.Values{
			"q":      []string{"text"},
			"target": []string{"es"},
		}},
		{language.English, []string{"text"}, &Options{}, url.Values{
			"q":      []string{"text"},
			"target": []string{"en"},
		}},
		{language.Turkish, []string{"t1", "t2"}, nil, url.Values{
			"q":      []string{"t1", "t2"},
			"target": []string{"tr"},
		}},
		{language.English, []string{"text"}, &Options{Source: language.French},
			url.Values{
				"q":      []string{"text"},
				"source": []string{"fr"},
				"target": []string{"en"},
			},
		},
		{language.English, []string{"text"}, &Options{Source: language.French, Format: HTML}, url.Values{
			"q":      []string{"text"},
			"source": []string{"fr"},
			"format": []string{"html"},
			"target": []string{"en"},
		}},
	} {
		_, err = c.Translate(ctx, test.inputs, test.target, test.opts)
		if err != nil {
			t.Fatal(err)
		}
		got := ft.req.URL.Query()
		test.want.Add("alt", "json")
		if !reflect.DeepEqual(got, test.want) {
			t.Errorf("Translate(%s, %v, %+v):\ngot  %s\nwant %s",
				test.target, test.inputs, test.opts, got, test.want)
		}
	}
}

// uploadBinary uploads the currently-running Linux binary.
// It crashes if it fails.
func (cl *cloudLaunch) uploadBinary() {
	ctx := context.Background()
	if cl.BinaryBucket == "" {
		log.Fatal("cloudlaunch: Config.BinaryBucket is empty")
	}
	stoClient, err := storage.NewClient(ctx, option.WithHTTPClient(cl.oauthClient))
	if err != nil {
		log.Fatal(err)
	}
	w := stoClient.Bucket(cl.BinaryBucket).Object(cl.binaryObject()).NewWriter(ctx)
	if err != nil {
		log.Fatal(err)
	}
	w.ACL = []storage.ACLRule{
		// If you don't give the owners access, the web UI seems to
		// have a bug and doesn't have access to see that it's public, so
		// won't render the "Shared Publicly" link. So we do that, even
		// though it's dumb and unnecessary otherwise:
		{
			Entity: storage.ACLEntity("project-owners-" + cl.GCEProjectID),
			Role:   storage.RoleOwner,
		},
		// Public, so our systemd unit can get it easily:
		{
			Entity: storage.AllUsers,
			Role:   storage.RoleReader,
		},
	}
	w.CacheControl = "no-cache"
	selfPath := getSelfPath()
	log.Printf("Uploading %q to %v", selfPath, cl.binaryURL())
	f, err := os.Open(selfPath)
	if err != nil {
		log.Fatal(err)
	}
	defer f.Close()
	n, err := io.Copy(w, f)
	if err != nil {
		log.Fatal(err)
	}
	if err := w.Close(); err != nil {
		log.Fatal(err)
	}
	log.Printf("Uploaded %d bytes", n)
}

// client returns the GCS Storage client instance.
// If there isn't one yet, it tries to create one.
func (bs *GCSBackupStorage) client() (*storage.Client, error) {
	bs.mu.Lock()
	defer bs.mu.Unlock()

	if bs._client == nil {
		// FIXME(alainjobart) add context.Context to BackupStorage API.
		ctx := context.TODO()
		authClient, err := google.DefaultClient(ctx)
		if err != nil {
			return nil, err
		}
		client, err := storage.NewClient(ctx, option.WithHTTPClient(authClient))
		if err != nil {
			return nil, err
		}
		bs._client = client
	}
	return bs._client, nil
}

func gcsCommonClient(client *http.Client, csctx *CloudStoreContext) (Store, error) {
	project := csctx.Project
	bucket := csctx.Bucket
	prefix := fmt.Sprintf("%s:(project=%s bucket=%s)", csctx.LogggingContext, project, bucket)
	l := LogConstructor(prefix)

	gcs, err := storage.NewClient(context.Background(), option.WithHTTPClient(client))
	if err != nil {
		l.Errorf("%v error creating Google cloud storage client. project:%s gs://%s/ err:%v ",
			csctx.LogggingContext, project, bucket, err)
		return nil, err
	}
	store, err := NewGCSStore(gcs, bucket, csctx.TmpDir, maxResults, l)
	if err != nil {
		l.Errorf("error creating the store. err=%v ", err)
		return nil, err
	}
	return store, nil
}

func TestErrorOnObjectsInsertCall(t *testing.T) {
	ctx := context.Background()
	hc := &http.Client{Transport: &fakeTransport{}}
	client, err := NewClient(ctx, option.WithHTTPClient(hc))
	if err != nil {
		t.Fatalf("error when creating client: %v", err)
	}
	wc := client.Bucket("bucketname").Object("filename1").NewWriter(ctx)
	wc.ContentType = "text/plain"

	// We can't check that the Write fails, since it depends on the write to the
	// underling fakeTransport failing which is racy.
	wc.Write([]byte("hello world"))

	// Close must always return an error though since it waits for the transport to
	// have closed.
	if err := wc.Close(); err == nil {
		t.Errorf("expected error on close, got nil")
	}
}

func init() {
	if !metadata.OnGCE() {
		return
	}
	hc, err := google.DefaultClient(oauth2.NoContext)
	if err != nil {
		registerBrokenFS(fmt.Errorf("could not get http client for context: %v", err))
		return
	}
	ctx := context.Background()
	sc, err := storage.NewClient(ctx, option.WithHTTPClient(hc))
	if err != nil {
		registerBrokenFS(fmt.Errorf("could not get cloud storage client: %v", err))
		return
	}
	wkfs.RegisterFS("/gcs/", &gcsFS{
		ctx: ctx,
		sc:  sc,
	})
}

func TestCopyToMissingFields(t *testing.T) {
	var tests = []struct {
		srcBucket, srcName, destBucket, destName string
		errMsg                                   string
	}{
		{
			"mybucket", "", "mybucket", "destname",
			"name is empty",
		},
		{
			"mybucket", "srcname", "mybucket", "",
			"name is empty",
		},
		{
			"", "srcfile", "mybucket", "destname",
			"name is empty",
		},
		{
			"mybucket", "srcfile", "", "destname",
			"name is empty",
		},
	}
	ctx := context.Background()
	client, err := NewClient(ctx, option.WithHTTPClient(&http.Client{Transport: &fakeTransport{}}))
	if err != nil {
		panic(err)
	}
	for i, test := range tests {
		src := client.Bucket(test.srcBucket).Object(test.srcName)
		dst := client.Bucket(test.destBucket).Object(test.destName)
		_, err := dst.CopierFrom(src).Run(ctx)
		if !strings.Contains(err.Error(), test.errMsg) {
			t.Errorf("CopyTo test #%v:\ngot err  %q\nwant err %q", i, err, test.errMsg)
		}
	}
}

// listDownloads lists all the files found in the monthly repo, and from them,
// builds the data that we'll feed to the template to generate the monthly
// downloads camweb page.
func listDownloads() (*ReleaseData, error) {
	ts, err := tokenSource(bucket)
	if err != nil {
		return nil, err
	}
	ctx := context.Background()
	stoClient, err := storage.NewClient(ctx, option.WithTokenSource(ts), option.WithHTTPClient(oauth2.NewClient(ctx, ts)))
	if err != nil {
		return nil, err
	}
	objList, err := stoClient.Bucket(bucket).List(ctx, &storage.Query{Prefix: "monthly/"})
	if err != nil {
		return nil, err
	}

	platformBySuffix := map[string]string{
		"src.zip":       "Source",
		"linux.tar.gz":  "Linux",
		"darwin.tar.gz": "Darwin",
		"windows.zip":   "Windows",
	}
	getPlatform := func(name string) string {
		for suffix, platform := range platformBySuffix {
			if strings.HasSuffix(name, suffix) {
				return platform
			}
		}
		return ""
	}
	getChecksum := func(name string) (string, error) {
		r, err := stoClient.Bucket(bucket).Object(name).NewReader(ctx)
		if err != nil {
			return "", err
		}
		var buf bytes.Buffer
		if _, err := io.Copy(&buf, r); err != nil {
			return "", err
		}
		return buf.String(), nil
	}
	var date time.Time
	checkDate := func(objDate time.Time) error {
		if date.IsZero() {
			date = objDate
			return nil
		}
		d := date.Sub(objDate)
		if d < 0 {
			d = -d
		}
		if d < 24*time.Hour {
			return nil
		}
		return fmt.Errorf("objects in monthly have not been uploaded or updated the same day")
	}

	var (
		downloadData []DownloadData
		nameToSum    = make(map[string]string)
	)
	fileDate := releaseDate.Format(fileDateFormat)
	for _, attrs := range objList.Results {
		if !strings.Contains(attrs.Name, fileDate) {
			continue
		}
		if err := checkDate(attrs.Updated); err != nil {
			return nil, err
		}
		if !strings.HasSuffix(attrs.Name, ".sha256") {
			continue
		}
		sum, err := getChecksum(attrs.Name)
		if err != nil {
			return nil, err
		}
		nameToSum[strings.TrimSuffix(attrs.Name, ".sha256")] = sum
	}
	for _, attrs := range objList.Results {
		if !strings.Contains(attrs.Name, fileDate) {
			continue
		}
		if strings.HasSuffix(attrs.Name, ".sha256") {
			continue
		}
		sum, ok := nameToSum[attrs.Name]
		if !ok {
			return nil, fmt.Errorf("%v has no checksum file!", attrs.Name)
		}
		downloadData = append(downloadData, DownloadData{
			Filename: filepath.Base(attrs.Name),
			Platform: getPlatform(attrs.Name),
			Checksum: sum,
		})
	}

	return &ReleaseData{
		Date:         releaseDate.Format(titleDateFormat),
//.........这里部分代码省略.........

// makeRequests makes some requests.
// req is an incoming request used to construct the trace.  traceClient is the
// client used to upload the trace.  rt is the trace client's http client's
// transport.  This is used to retrieve the trace uploaded by the client, if
// any.  If expectTrace is true, we expect a trace will be uploaded.  If
// synchronous is true, the call to Finish is expected not to return before the
// client has uploaded any traces.
func makeRequests(t *testing.T, req *http.Request, traceClient *Client, rt *fakeRoundTripper, synchronous bool, expectTrace bool) *http.Request {
	span := traceClient.SpanFromRequest(req)
	ctx := NewContext(context.Background(), span)

	// An HTTP request.
	{
		req2, err := http.NewRequest("GET", "http://example.com/bar", nil)
		if err != nil {
			t.Fatal(err)
		}
		resp := &http.Response{StatusCode: 200}
		s := span.NewRemoteChild(req2)
		s.Finish(WithResponse(resp))
	}

	// An autogenerated API call.
	{
		rt := &fakeRoundTripper{reqc: make(chan *http.Request, 1)}
		hc := &http.Client{Transport: rt}
		computeClient, err := compute.New(hc)
		if err != nil {
			t.Fatal(err)
		}
		_, err = computeClient.Zones.List(testProjectID).Context(ctx).Do()
		if err != nil {
			t.Fatal(err)
		}
	}

	// A cloud library call that uses the autogenerated API.
	{
		rt := &fakeRoundTripper{reqc: make(chan *http.Request, 1)}
		hc := &http.Client{Transport: rt}
		storageClient, err := storage.NewClient(context.Background(), option.WithHTTPClient(hc))
		if err != nil {
			t.Fatal(err)
		}
		var objAttrsList []*storage.ObjectAttrs
		it := storageClient.Bucket("testbucket").Objects(ctx, nil)
		for {
			objAttrs, err := it.Next()
			if err != nil && err != iterator.Done {
				t.Fatal(err)
			}
			if err == iterator.Done {
				break
			}
			objAttrsList = append(objAttrsList, objAttrs)
		}
	}

	// A cloud library call that uses grpc internally.
	for _, fail := range []bool{false, true} {
		srv, err := testutil.NewServer()
		if err != nil {
			t.Fatalf("creating test datastore server: %v", err)
		}
		dspb.RegisterDatastoreServer(srv.Gsrv, &fakeDatastoreServer{fail: fail})
		srv.Start()
		conn, err := grpc.Dial(srv.Addr, grpc.WithInsecure(), EnableGRPCTracingDialOption)
		if err != nil {
			t.Fatalf("connecting to test datastore server: %v", err)
		}
		datastoreClient, err := datastore.NewClient(ctx, testProjectID, option.WithGRPCConn(conn))
		if err != nil {
			t.Fatalf("creating datastore client: %v", err)
		}
		k := datastore.NameKey("Entity", "stringID", nil)
		e := new(datastore.Entity)
		datastoreClient.Get(ctx, k, e)
	}

	done := make(chan struct{})
	go func() {
		if synchronous {
			err := span.FinishWait()
			if err != nil {
				t.Errorf("Unexpected error from span.FinishWait: %v", err)
			}
		} else {
			span.Finish()
		}
		done <- struct{}{}
	}()
	if !expectTrace {
		<-done
		select {
		case <-rt.reqc:
			t.Errorf("Got a trace, expected none.")
		case <-time.After(5 * time.Millisecond):
		}
		return nil
	} else if !synchronous {
//.........这里部分代码省略.........

// WithBaseHTTP returns a ClientOption that specifies the HTTP client to
// use as the basis of communications. This option may only be used with
// services that support HTTP as their communication transport.
func WithBaseHTTP(client *http.Client) ClientOption {
	return wrapOpt{option.WithHTTPClient(client)}
}

//.........这里部分代码省略.........
			contents: [][]byte{},
			size:     0,
			md5:      "d41d8cd98f00b204e9800998ecf8427e",
			crc32c:   0,
		},
	}
	for _, c := range checksumCases {
		wc := bkt.Object(c.name).NewWriter(ctx)
		for _, data := range c.contents {
			if _, err := wc.Write(data); err != nil {
				t.Errorf("Write(%q) failed with %q", data, err)
			}
		}
		if err = wc.Close(); err != nil {
			t.Errorf("%q: close failed with %q", c.name, err)
		}
		obj := wc.Attrs()
		if got, want := obj.Size, c.size; got != want {
			t.Errorf("Object (%q) Size = %v; want %v", c.name, got, want)
		}
		if got, want := fmt.Sprintf("%x", obj.MD5), c.md5; got != want {
			t.Errorf("Object (%q) MD5 = %q; want %q", c.name, got, want)
		}
		if got, want := obj.CRC32C, c.crc32c; got != want {
			t.Errorf("Object (%q) CRC32C = %v; want %v", c.name, got, want)
		}
	}

	// Test public ACL.
	publicObj := objects[0]
	if err = bkt.Object(publicObj).ACL().Set(ctx, AllUsers, RoleReader); err != nil {
		t.Errorf("PutACLEntry failed with %v", err)
	}
	publicClient, err := NewClient(ctx, option.WithHTTPClient(http.DefaultClient))
	if err != nil {
		t.Fatal(err)
	}
	rc, err := publicClient.Bucket(bucket).Object(publicObj).NewReader(ctx)
	if err != nil {
		t.Error(err)
	}
	slurp, err := ioutil.ReadAll(rc)
	if err != nil {
		t.Errorf("ReadAll failed with %v", err)
	}
	if !bytes.Equal(slurp, contents[publicObj]) {
		t.Errorf("Public object's content: got %q, want %q", slurp, contents[publicObj])
	}
	rc.Close()

	// Test writer error handling.
	wc := publicClient.Bucket(bucket).Object(publicObj).NewWriter(ctx)
	if _, err := wc.Write([]byte("hello")); err != nil {
		t.Errorf("Write unexpectedly failed with %v", err)
	}
	if err = wc.Close(); err == nil {
		t.Error("Close expected an error, found none")
	}

	// Test deleting the copy object.
	if err := bkt.Object(copyName).Delete(ctx); err != nil {
		t.Errorf("Deletion of %v failed with %v", copyName, err)
	}
	// Deleting it a second time should return ErrObjectNotExist.
	if err := bkt.Object(copyName).Delete(ctx); err != ErrObjectNotExist {
		t.Errorf("second deletion of %v = %v; want ErrObjectNotExist", copyName, err)

// makeRequests makes some requests.
// req is an incoming request used to construct the trace.  traceClient is the
// client used to upload the trace.  rt is the trace client's http client's
// transport.  This is used to retrieve the trace uploaded by the client, if
// any.  If expectTrace is true, we expect a trace will be uploaded.  If
// synchronous is true, the call to Finish is expected not to return before the
// client has uploaded any traces.
func makeRequests(t *testing.T, req *http.Request, traceClient *Client, rt *fakeRoundTripper, synchronous bool, expectTrace bool) *http.Request {
	span := traceClient.SpanFromRequest(req)
	ctx := NewContext(context.Background(), span)

	// An HTTP request.
	{
		req2, err := http.NewRequest("GET", "http://example.com/bar", nil)
		if err != nil {
			t.Fatal(err)
		}
		resp := &http.Response{StatusCode: 200}
		s := span.NewRemoteChild(req2)
		s.Finish(WithResponse(resp))
	}

	// An autogenerated API call.
	{
		rt := &fakeRoundTripper{reqc: make(chan *http.Request, 1)}
		hc := &http.Client{Transport: rt}
		computeClient, err := compute.New(hc)
		if err != nil {
			t.Fatal(err)
		}
		_, err = computeClient.Zones.List(testProjectID).Context(ctx).Do()
		if err != nil {
			t.Fatal(err)
		}
	}

	// A cloud library call that uses the autogenerated API.
	{
		rt := &fakeRoundTripper{reqc: make(chan *http.Request, 1)}
		hc := &http.Client{Transport: rt}
		storageClient, err := storage.NewClient(context.Background(), option.WithHTTPClient(hc))
		if err != nil {
			t.Fatal(err)
		}
		var objAttrsList []*storage.ObjectAttrs
		it := storageClient.Bucket("testbucket").Objects(ctx, nil)
		for {
			objAttrs, err := it.Next()
			if err != nil && err != storage.Done {
				t.Fatal(err)
			}
			if err == storage.Done {
				break
			}
			objAttrsList = append(objAttrsList, objAttrs)
		}
	}

	done := make(chan struct{})
	go func() {
		if synchronous {
			err := span.FinishWait()
			if err != nil {
				t.Errorf("Unexpected error from span.FinishWait: %v", err)
			}
		} else {
			span.Finish()
		}
		done <- struct{}{}
	}()
	if !expectTrace {
		<-done
		select {
		case <-rt.reqc:
			t.Errorf("Got a trace, expected none.")
		case <-time.After(5 * time.Millisecond):
		}
		return nil
	} else if !synchronous {
		<-done
		return <-rt.reqc
	} else {
		select {
		case <-done:
			t.Errorf("Synchronous Finish didn't wait for trace upload.")
			return <-rt.reqc
		case <-time.After(5 * time.Millisecond):
			r := <-rt.reqc
			<-done
			return r
		}
	}
}