// 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.

// https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html
// Returns ErrInvalidChecksum if a problem with the checksum is found.
func (r *Reader) AddChecksumNoTrailer(headers http.Header, ignoreValue bool) error {
	cs, err := GetContentChecksum(headers)
	if err != nil {
		return ErrInvalidChecksum
	}
	if cs == nil {
		return nil
	}
	r.contentHash = *cs
	return r.AddNonTrailingChecksum(cs, ignoreValue)
}

}

// 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

	// The format of the original Unix V7 tar tool prior to standardization.
	formatV7

	// FormatUSTAR represents the USTAR header format defined in POSIX.1-1988.
	//
	// While this format is compatible with most tar readers,
	// the format has several limitations making it unsuitable for some usages.
	// Most notably, it cannot support sparse files, files larger than 8GiB,
	// filenames larger than 256 characters, and non-ASCII filenames.
	//

	Comment string

	// NonUTF8 indicates that Name and Comment are not encoded in UTF-8.
	//
	// By specification, the only other encoding permitted should be CP-437,
	// but historically many ZIP readers interpret Name and Comment as whatever
	// the system's local character encoding happens to be.
	//
	// This flag should only be set if the user intends to encode a non-portable

	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: