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)

	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

		{testBuckets[0], "unique/folder/1.txt", "content", nil, false},
		{testBuckets[1], "unique/folder/1.txt", "content", nil, true},
	}
	for _, object := range testObjects {
		md5Bytes := md5.Sum([]byte(object.content))
		_, err = obj.PutObject(context.Background(), object.parentBucket, object.name, mustGetPutObjReader(t, bytes.NewBufferString(object.content),

)

// 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" +

   */
  protected long edgeCount() {
    long degreeSum = 0L;
    for (N node : nodes()) {
      degreeSum += degree(node);
    }
    // According to the degree sum formula, this is equal to twice the number of edges.
    checkState((degreeSum & 1) == 0);
    return degreeSum >>> 1;
  }

  /**

     * estimate without locking. Note that the number, if not exactly accurate, is *always*
     * underestimating, never overestimating.
     */
    long bitCount() {
      return bitCount.sum();
    }

    LockFreeBitArray copy() {
      return new LockFreeBitArray(toPlainArray(data));
    }

    /**
     * Combines the two BitArrays using bitwise OR.
     *

##########################################################################################
# End of extension
##########################################################################################

# If specified, validate the SHA-256 sum of the Maven wrapper jar file
wrapperSha256Sum=""
while IFS="=" read -r key value; do
  case "$key" in wrapperSha256Sum)
    wrapperSha256Sum=$value
    break
    ;;
  esac

	}
	uploadID := res.UploadID

	// Upload part1.
	fiveMBBytes := bytes.Repeat([]byte("a"), 5*humanize.MiByte)
	md5Writer := md5.New()
	md5Writer.Write(fiveMBBytes)
	etag1 := hex.EncodeToString(md5Writer.Sum(nil))
	sha256sum := ""
	_, err = obj.PutObjectPart(context.Background(), bucket, object, uploadID, 1, mustGetPutObjReader(t, bytes.NewReader(fiveMBBytes), int64(len(fiveMBBytes)), etag1, sha256sum), opts)
	if err != nil {

	}
	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 {

    
    private ChannelInfo selectWeightedRandom(Collection<ChannelInfo> channels) {
        // Calculate total weight
        int totalWeight = channels.stream()
            .mapToInt(ChannelInfo::getScore)
            .sum();
        
        if (totalWeight == 0) {
            // All channels have zero score, pick randomly
            List<ChannelInfo> list = new ArrayList<>(channels);