//	   if err != nil {
//	   }
//	}
//	ETag = ETag.Format()
func (e ETag) Format() ETag {
	if !e.IsEncrypted() {
		return e
	}
	return e[len(e)-16:]
}

var _ Tagger = ETag{} // compiler check

// ETag returns the ETag itself.
//
// By providing this method ETag implements
// the Tagger interface.
func (e ETag) ETag() ETag { return e }

var stringTests = []struct {
	ETag   ETag
	String string
}{
	{ETag: ETag{59, 131, 239, 150, 56, 127, 20, 101}, String: "3b83ef96387f1465"},                                                                  // 0
	{ETag: ETag{59, 131, 239, 150, 56, 127, 20, 101, 95, 200, 84, 221, 195, 198, 189, 87}, String: "3b83ef96387f14655fc854ddc3c6bd57"},             // 1

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"sigs.k8s.io/controller-runtime/pkg/client"

	"istio.io/api/operator/v1alpha1"
	"istio.io/istio/istioctl/pkg/cli"
	"istio.io/istio/istioctl/pkg/clioptions"
	revtag "istio.io/istio/istioctl/pkg/tag"
	"istio.io/istio/istioctl/pkg/util"
	v1alpha12 "istio.io/istio/operator/pkg/apis/istio/v1alpha1"
	"istio.io/istio/operator/pkg/cache"
	"istio.io/istio/operator/pkg/helmreconciler"

			want:     true,
		},
		{
			filter:   noTags,
			userTags: "A=3",
			want:     true,
		},
		{
			filter:   oneTag,
			userTags: "A=3",
			want:     false,
		},
		{
			filter:   oneTag,
			userTags: "FOO=1",
			want:     true,
		},
		{
			filter:   oneTag,
			userTags: "A=B&FOO=1",
			want:     true,
		},
		{
			filter:   twoTags,
			userTags: "",
			want:     false,

		etag = commonETag(etags, quorum)

		if etag != "" { // allow this fallback only if a non-empty etag is found.
			for index, e := range etags {
				if partsMetadata[index].IsValid() && e == etag {
					onlineDisks[index] = disks[index]
				} else {
					onlineDisks[index] = nil
				}
			}
			return onlineDisks, modTime, etag
		}
	}

			if _, ok := crypto.IsEncrypted(batch[i].UserDefined); ok {
				ETag, err := etag.Parse(batch[i].ETag)
				if err != nil {
					return err
				}
				if SSES3SinglePartObjects[i] && ETag.IsEncrypted() {
					ETag, err = etag.Decrypt(keys[0][:], ETag)
					if err != nil {
						return err
					}
					keys = keys[1:]
				}
				batch[i].ETag = ETag.Format().String()
			}
		}
		objects = objects[N:]
	}

func UTCNow() time.Time {
	return time.Now().UTC()
}

// GenETag - generate UUID based ETag
func GenETag() string {
	return ToS3ETag(getMD5Hash([]byte(mustGetUUID())))
}

// ToS3ETag - return checksum to ETag
func ToS3ETag(etag string) string {
	etag = canonicalizeETag(etag)

	if !strings.HasSuffix(etag, "-1") {
		// Tools like s3cmd uses ETag as checksum of data to validate.

// generates CopyObjectResponse from etag and lastModified time.
func generateCopyObjectResponse(etag string, lastModified time.Time) CopyObjectResponse {
	return CopyObjectResponse{
		ETag:         "\"" + etag + "\"",
		LastModified: amztime.ISO8601Format(lastModified.UTC()),
	}
}

// generates CopyObjectPartResponse from etag and lastModified time.

	// Set last modified time.
	lastModified := objInfo.ModTime.UTC().Format(http.TimeFormat)
	w.Header().Set(xhttp.LastModified, lastModified)

	// Set Etag if available.
	if objInfo.ETag != "" {
		w.Header()[xhttp.ETag] = []string{"\"" + objInfo.ETag + "\""}
	}

	if objInfo.ContentType != "" {
		w.Header().Set(xhttp.ContentType, objInfo.ContentType)
	}

	if objInfo.ContentEncoding != "" {

	respHeader := make(map[string]string, len(wh))
	for k, v := range wh {
		respHeader[k] = strings.Join(v, ",")
	}
	entry.RespHeader = respHeader

	if etag := respHeader[xhttp.ETag]; etag != "" {
		respHeader[xhttp.ETag] = strings.Trim(etag, `"`)
	}

	return entry