// expecting a failure during upload.
	response, err = s.client.Do(request)
	c.Assert(err, nil)
	// Since Content-Md5 header was wrong, expecting to fail with "SignatureDoesNotMatch" error.
	verifyError(c, response, "SignatureDoesNotMatch", "The request signature we calculated does not match the signature you provided. Check your key and signing method.", http.StatusForbidden)
}