func (set TargetIDSet) add(targetID TargetID) {
	set[targetID] = struct{}{}
}

// Union - returns union with given set as new set.
func (set TargetIDSet) Union(sset TargetIDSet) TargetIDSet {
	nset := set.Clone()

	for k := range sset {
		nset.add(k)
	}

	return nset
}

// Difference - returns difference with given set as new set.
func (set TargetIDSet) Difference(sset TargetIDSet) TargetIDSet {

func (set TargetIDSet) add(targetID TargetID) {
	set[targetID] = struct{}{}
}

// Union - returns union with given set as new set.
func (set TargetIDSet) Union(sset TargetIDSet) TargetIDSet {
	nset := set.Clone()

	for k := range sset {
		nset.add(k)
	}

	return nset
}

// Difference - returns difference with given set as new set.
func (set TargetIDSet) Difference(sset TargetIDSet) TargetIDSet {

	e := json.NewEncoder(&buf)
	d := jstream.NewDecoder(r, 0).ObjectAsKVS()
	sset := set.NewStringSet()
	for mv := range d.Stream() {
		var kvs jstream.KVS
		if mv.ValueType == jstream.Object {
			// This is a JSON object type (that preserves key order)
			kvs = mv.Value.(jstream.KVS)
			for _, kv := range kvs {
				if sset.Contains(kv.Key) {
					// Reject duplicate conditions or expiration.

			}
		case crypto.S3:
			w.Header().Set(xhttp.AmzServerSideEncryption, xhttp.AmzEncryptionAES)
			etag, _ = DecryptETag(objectEncryptionKey, ObjectInfo{ETag: etag})
		case crypto.SSEC:
			w.Header().Set(xhttp.AmzServerSideEncryptionCustomerAlgorithm, r.Header.Get(xhttp.AmzServerSideEncryptionCustomerAlgorithm))
			w.Header().Set(xhttp.AmzServerSideEncryptionCustomerKeyMD5, r.Header.Get(xhttp.AmzServerSideEncryptionCustomerKeyMD5))

	if err != nil || c == nil {
		return
	}
	t, s := c.Type, c.Encoded
	if !c.Type.IsSet() {
		return
	}
	if c.Type.Is(ChecksumTrailing) {
		val := r.Trailer.Get(t.Key())
		if val != "" {
			w.Header().Set(t.Key(), val)
		}
		return
	}
	w.Header().Set(t.Key(), s)
}

// AddChecksumHeader will transfer any checksum value that has been checked.

	defer func(l bool) { logger.DisableErrorLog = l }(logger.DisableErrorLog)
	logger.DisableErrorLog = true
	for i, test := range ssecCreateMetadataTests {
		metadata := SSEC.CreateMetadata(nil, test.SealedKey)
		sealedKey, err := SSEC.ParseMetadata(metadata)
		if err != nil {
			t.Errorf("Test %d: failed to parse metadata: %v", i, err)
			continue
		}
		if sealedKey.Algorithm != test.SealedKey.Algorithm {

			w.Header().Set(xhttp.AmzServerSideEncryptionKmsContext, kmsCtx)
		}
	case crypto.SSEC:
		// Validate the SSE-C Key set in the header.
		if _, err = crypto.SSEC.UnsealObjectKey(r.Header, objInfo.UserDefined, bucket, object); err != nil {
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
			return
		}

				return
			}
		case "pool":
			z.pool, err = dc.ReadInt()
			if err != nil {
				err = msgp.WrapError(err, "pool")
				return
			}
		case "set":
			z.set, err = dc.ReadInt()
			if err != nil {
				err = msgp.WrapError(err, "set")
				return
			}
		default:
			err = dc.Skip()
			if err != nil {
				err = msgp.WrapError(err)
				return
			}
		}
	}
	return
}

// when bucketSSEConfig is empty.
type ApplyOptions struct {
	AutoEncrypt bool
}

// Apply applies the SSE bucket configuration on the given HTTP headers and
// sets the specified SSE headers.
//
// Apply does not overwrite any existing SSE headers. Further, it will
// set minimal SSE-KMS headers if autoEncrypt is true and the BucketSSEConfig
// is nil.

	return xattr.LSet(path, name, data)
}

func main() {
	flag.StringVar(&path, "path", "", "path name where the attribute shall be applied")
	flag.StringVar(&name, "name", "", "attribute name or it can be a wildcard if '.' is specified")
	flag.Uint64Var(&value, "value", 0, "attribute value expects the value to be uint64")
	flag.BoolVar(&set, "set", false, "this is a set attribute operation")

	flag.Parse()