// JoinLoaders - joins multiple loaders into a single loader. The returned
// loader will call each of the given loaders in order. If any of the loaders
// return an error, the returned loader will return that error.
func JoinLoaders(loaders ...MetricsLoaderFn) MetricsLoaderFn {
	return func(ctx context.Context, m MetricValues, c *metricsCache) error {
		for _, loader := range loaders {
			if err := loader(ctx, m, c); err != nil {

				"response-content-type": "application/json",
			},
			headers: map[string]string{
				"X-Amz-Date":           now.Format(iso8601Format),
				"X-Amz-Content-Sha256": payloadSHA256,
			},
			region:   "",
			expected: ErrSignatureDoesNotMatch,
		},
		// (9) Should error with unsigned headers.
		{
			queryParams: map[string]string{
				"X-Amz-Algorithm":       signV4Algorithm,

	}

	// Since the list of signed headers value contained `expect`, the default value of `100-continue` will be added to extracted signed headers.
	if extractedExpect != expectedExpect {
		t.Errorf("expect header incorrect value: expected `%s`, got `%s`", expectedExpect, extractedExpect)
	}

	// case where the headers don't contain the one of the signed header in the signed headers list.

		// If request header key is not in ignored headers, then add it.
		if _, ok := ignoredStreamingHeaders[http.CanonicalHeaderKey(k)]; !ok {
			headerMap[strings.ToLower(k)] = vv
		}
	}

	// Get header keys.
	headers := []string{"host"}
	for k := range headerMap {
		headers = append(headers, k)
	}
	sort.Strings(headers)

	// Get canonical headers.
	var buf bytes.Buffer
	for _, k := range headers {

		if testCase.expectedCode != actualCode {
			t.Errorf("Test %d: Expected the APIErrCode to be %d, but instead found %d", i+1, testCase.expectedCode, actualCode)
		}
	}
}

// Tests validate metadata extraction from http headers.
func TestExtractMetadataHeaders(t *testing.T) {
	testCases := []struct {
		header     http.Header
		metadata   map[string]string
		shouldFail bool
	}{
		// Validate if there a known 'content-type'.
		{

	v := MRFReplicateEntries{
		Entries: entries,
		Version: mrfMetaVersion,
	}

	p.persistToDrive(ctx, v)
}

// load mrf entries from disk
func (p *ReplicationPool) loadMRF() (mrfRec MRFReplicateEntries, err error) {
	loadMRF := func(rc io.ReadCloser) (re MRFReplicateEntries, err error) {
		defer rc.Close()

		if !p.initialized() {
			return re, nil
		}
		var data [4]byte

}

// Set of s3 handler options as bit flags.
type s3HFlag uint8

const (
	// when provided, disables Gzip compression.
	noGZS3HFlag = 1 << iota

	// when provided, enables only tracing of headers. Otherwise, both headers
	// and body are traced.
	traceHdrsS3HFlag

	// when provided, disables throttling via the `maxClients` middleware.
	noThrottleS3HFlag
)

func (h s3HFlag) has(flag s3HFlag) bool {

}()

// Set of handler options as bit flags
type hFlag uint8

const (
	// this flag disables gzip compression of responses
	noGZFlag = 1 << iota

	// this flag enables tracing body and headers instead of just headers
	traceAllFlag

	// pass this flag to skip checking if object layer is available
	noObjLayerFlag
)

// Has checks if the given flag is enabled in `h`.
func (h hFlag) Has(flag hFlag) bool {

	UploadID string

	// Date and time at which the multipart upload was initiated.
	Initiated time.Time

	// Any metadata set during InitMultipartUpload, including encryption headers.
	UserDefined map[string]string
}

// ListPartsInfo - represents list of all parts.
type ListPartsInfo struct {
	// Name of the bucket.
	Bucket string

	// Name of the object.
	Object string

	if err != nil {
		if err == errConfigNotFound {
			return errNoSuchUser
		}
		return err
	}
	return ies.addUser(ctx, user, userType, u, m)
}

func (ies *IAMEtcdStore) loadUsers(ctx context.Context, userType IAMUserType, m map[string]UserIdentity) error {
	var basePrefix string
	switch userType {
	case svcUser:
		basePrefix = iamConfigServiceAccountsPrefix
	case stsUser: