code: func (lo *largeObject) putMd5() (err error) {
  	calcMd5 := fmt.Sprintf("%x", lo.md5.Sum(nil))
  	md5Reader := strings.NewReader(calcMd5)
  	lo.logger.Debug(swiftLargeObjectLogTag, fmt.Sprintf("Put md5: %s of object: %s", calcMd5, lo.container+"/"+lo.objectName+".md5"))
  	_, err = lo.c.ObjectPut(lo.container, lo.objectName+".md5", md5Reader, true, "", "", nil)
  	return
  }
docs: // Put md5 file in .md5 subdirectory of bucket  where the file is stored
  // e.g. the md5 for https://mybucket.s3.amazonaws.com/gof3r will be stored in
  // https://mybucket.s3.amazonaws.com/gof3r.md5