// Add some files to the archive.
	var files = []struct {
		Name, Body string
	}{
		{"readme.txt", "This archive contains some text files."},
		{"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"},
		{"todo.txt", "Get animal handling licence.\nWrite more examples."},
	}
	for _, file := range files {
		f, err := w.Create(file.Name)
		if err != nil {
			log.Fatal(err)
		}
		_, err = f.Write([]byte(file.Body))
		if err != nil {

	tw := tar.NewWriter(&buf)
	var files = []struct {
		Name, Body string
	}{
		{"readme.txt", "This archive contains some text files."},
		{"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"},
		{"todo.txt", "Get animal handling license."},
	}
	for _, file := range files {
		hdr := &tar.Header{
			Name: file.Name,
			Mode: 0600,
			Size: int64(len(file.Body)),
		}
		if err := tw.WriteHeader(hdr); err != nil {

	sum := hasher.Sum(nil)
	if !bytes.Equal(sum, c.Raw) {
		return ChecksumMismatch{
			Want: c.Encoded,
			Got:  base64.StdEncoding.EncodeToString(sum),
		}
	}
	return nil
}

// AsMap returns the
func (c *Checksum) AsMap() map[string]string {
	if c == nil || !c.Valid() {
		return nil
	}
	return map[string]string{c.Type.String(): c.Encoded}
}

	animal.Name = "amazing horse"
	DB.Save(&animal)
	DB.First(&animal, animal.Counter)
	if animal.Name != "amazing horse" {
		t.Errorf("Update a filed with a default value should occur. But got %v\n", animal.Name)
	}

	// When changing a field with a default value with blank value
	animal.Name = ""
	DB.Save(&animal)
	DB.First(&animal, animal.Counter)
	if animal.Name != "" {

		redirectURL.RawQuery = v.Encode()
		writeRedirectSeeOther(w, redirectURL.String())
		return
	}

	// Add checksum header.
	if checksum != nil && checksum.Valid() {
		hash.AddChecksumHeader(w, checksum.AsMap())
	}

	// Decide what http response to send depending on success_action_status parameter
	switch successStatus {
	case "201":
		resp := encodeResponse(PostResponse{
			Bucket:   objInfo.Bucket,