return cred, owner, ErrNone
}

// sumHMAC calculate hmac between two input byte array.
func sumHMAC(key []byte, data []byte) []byte {
	hash := hmac.New(sha256.New, key)
	hash.Write(data)
	return hash.Sum(nil)
}

// extractSignedHeaders extract signed headers from Authorization header
func extractSignedHeaders(signedHeaders []string, r *http.Request) (http.Header, APIErrorCode) {
	reqHeaders := r.Header

		}
	)

	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 sum
	}

	// set of inputs for uploading the objects before tests for
	// downloading is done. Data bytes are from DummyDataGen.
	objectInputs := []ObjectInput{

  verbose " - Running Downloader.java ..."
  "$(native_path "$JAVACMD")" -cp "$(native_path "$TMP_DOWNLOAD_DIR")" Downloader "$distributionUrl" "$(native_path "$targetZip")"
fi

# If specified, validate the SHA-256 sum of the Maven distribution zip file
if [ -n "${distributionSha256Sum-}" ]; then
  distributionSha256Result=false
  if [ "$MVN_CMD" = mvnd.sh ]; then
    echo "Checksum validation is not supported for maven-mvnd." >&2

	}
	return ErrNone
}

func calculateSignatureV2(stringToSign string, secret string) string {
	hm := hmac.New(sha1.New, []byte(secret))
	hm.Write([]byte(stringToSign))
	return base64.StdEncoding.EncodeToString(hm.Sum(nil))
}

// Return signature-v2 for the presigned request.
func preSignatureV2(cred auth.Credentials, method string, encodedResource string, encodedQuery string, headers http.Header, expires string) string {

		"}"
    if "%MVNW_VERBOSE%" == "true" (
        echo Finished downloading %WRAPPER_JAR%
    )
)
@REM End of extension

@REM If specified, validate the SHA-256 sum of the Maven wrapper jar file
SET WRAPPER_SHA_256_SUM=""
FOR /F "usebackq tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
    IF "%%A"=="wrapperSha256Sum" SET WRAPPER_SHA_256_SUM=%%B

        Keras training loops like `fit`/`evaluate`, the unreduced vector loss is
        passed to the optimizer but the reported loss will be a scalar value.
    *   `SUM`: Scalar sum of weighted losses. 4. `SUM_OVER_BATCH_SIZE`: Scalar
        `SUM` divided by number of elements in losses. This reduction type is
        not supported when used with `tf.distribute.Strategy` outside of
        built-in training loops like `tf.keras` `compile`/`fit`.

)

// getChunkSignature - get chunk signature.
// Does not update anything in cr.
func (cr *s3ChunkedReader) getChunkSignature() string {
	hashedChunk := hex.EncodeToString(cr.chunkSHA256Writer.Sum(nil))

	// Calculate string to sign.
	alg := signV4ChunkedAlgorithm + "\n"
	stringToSign := alg +
		cr.seedDate.Format(iso8601Format) + "\n" +
		getScope(cr.seedDate, cr.region) + "\n" +
		cr.seedSignature + "\n" +

    // vol. 2, Knuth, 4.2.2, (16) to the two-variable case. We have two value series x_i and y_i.
    // We define the arithmetic means X_n = 1/n \sum_{i=1}^n x_i, and Y_n = 1/n \sum_{i=1}^n y_i.
    // We also define the sum of the products of the differences from the means
    //           C_n = \sum_{i=1}^n x_i y_i - n X_n Y_n
    // for all n >= 1. Then for all n > 1:
    //       C_{n-1} = \sum_{i=1}^{n-1} x_i y_i - (n-1) X_{n-1} Y_{n-1}

	if err != nil {
		logger.Error("Calculating checksum failed: %s", err)
		return "00000000000000000000000000000000"
	}

	defer b.Close()
	io.Copy(mw, b)
	return hex.EncodeToString(mw.Sum(nil))
}

func verifyServerSystemConfig(ctx context.Context, endpointServerPools EndpointServerPools, gm *grid.Manager) error {
	srcCfg := getServerSystemCfg()
	clnts := newBootstrapRESTClients(endpointServerPools, gm)

		t.Errorf("Should find expected results, got %+v", results)
	}

	var ages int
	if err := DB.Table("users").Where("name = ? or name = ?", user2.Name, user3.Name).Select("SUM(age)").Scan(&ages).Error; err != nil || ages != 30 {
		t.Fatalf("failed to scan ages, got error %v, ages: %v", err, ages)
	}

	var name string