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 {
		// Failed to upload object part, abort.