// and If-Unmodified-Since headers set are validated.
// If-Modified-Since - Return the object only if it has been modified since the specified time, else return a 304 (not modified).
// If-Unmodified-Since - Return the object only if it has not been modified since the specified time, else return a 412 (precondition failed).
func (s *TestSuiteCommon) TestHeadOnObjectLastModified(c *check) {

	}
	err = en.WriteInt64(z.Size)
	if err != nil {
		err = msgp.WrapError(err, "Size")
		return
	}
	// write "os"
	err = en.Append(0xa2, 0x6f, 0x73)
	if err != nil {
		return
	}
	err = en.WriteUint64(z.Objects)
	if err != nil {
		err = msgp.WrapError(err, "Objects")
		return
	}
	// write "vs"
	err = en.Append(0xa2, 0x76, 0x73)
	if err != nil {
		return
	}

	if err != nil {
		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
		return
	}

	opts, err := getOpts(ctx, r, bucket, object)
	if err != nil {
		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
		return
	}

	getObjectInfo := objectAPI.GetObjectInfo

	// Check for auth type to return S3 compatible error.
	// type to return the correct error (NoSuchKey vs AccessDenied)

		if globalTierConfigMgr.Empty() {
			return
		}

		dui, err := loadDataUsageFromBackend(ctx, objLayer)
		if err != nil {
			metricsLogIf(ctx, err)
			return
		}
		// data usage has not captured any tier stats yet.
		if dui.TierStats == nil {
			return
		}

		return dui.tierMetrics()
	})
	return mg
}

// in front of MinIO.
func checkRemoteEndpoint(ctx context.Context, epURL *url.URL) error {
	reqURL := &url.URL{
		Scheme: epURL.Scheme,
		Host:   epURL.Host,
		Path:   healthCheckPathPrefix + healthCheckReadinessPath,
	}

	req, err := http.NewRequestWithContext(ctx, http.MethodGet, reqURL.String(), nil)
	if err != nil {
		return err
	}

	client := &http.Client{
		Transport: globalRemoteTargetTransport,

			for k, v := range m {
				r[k] = v
			}
			return r
		}
	)

	type ObjectInput struct {
		objectName  string
		partLengths []int64

		metaData map[string]string
	}

	objectLength := func(oi ObjectInput) (sum int64) {
		for _, l := range oi.partLengths {
			sum += l
		}
		return
	}

	// set of inputs for uploading the objects before tests for