func runPutObjectPartBenchmark(b *testing.B, obj ObjectLayer, partSize int) {
	var err error
	// obtains random bucket name.
	bucket := getRandomBucketName()
	object := getRandomObjectName()

	// create bucket.
	err = obj.MakeBucket(context.Background(), bucket, MakeBucketOptions{})
	if err != nil {
		b.Fatal(err)
	}

	objSize := 128 * humanize.MiByte

	objLayer, _, err := initObjectLayer(ctx, mustGetPoolEndpoints(0, fsDirs...))
	if err != nil {
		t.Fatal(err)
	}

	setObjectLayer(objLayer)

	bucket := getRandomBucketName()
	object := getRandomObjectName()
	data := bytes.Repeat([]byte("a"), 128*1024)

	err = objLayer.MakeBucket(ctx, bucket, MakeBucketOptions{})
	if err != nil {
		t.Fatalf("Failed to make a bucket - %v", err)
	}

			b[i] = letterBytes[idx]
			i--
		}
		cache >>= letterIdxBits
		remain--
	}

	return *(*string)(unsafe.Pointer(&b))
}

// generate random object name.
func getRandomObjectName() string {
	return randString(16)
}

// generate random bucket name.
func getRandomBucketName() string {
	return randString(60)
}

}

func (s *TestSuiteIAM) TestSTSWithTags(c *check) {
	ctx, cancel := context.WithTimeout(context.Background(), testDefaultTimeout)
	defer cancel()

	bucket := getRandomBucketName()
	object := getRandomObjectName()
	err := s.client.MakeBucket(ctx, bucket, minio.MakeBucketOptions{})
	if err != nil {
		c.Fatalf("bucket creat error: %v", err)
	}

	// Create policy, user and associate policy
	policy := "mypolicy"