You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: table_test.go
    path of file: ./repos/storj/storagenode/piecestore/usedserials
    
    the code of the file until where you have to start completion: // Copyright (C) 2020 Storj Labs, Inc.
// See LICENSE for copying information.

package usedserials_test

import (
	"encoding/binary"
	"testing"
	"time"

	"github.com/stretchr/testify/requ
    
func createExpirationSerial(originalSerial storj.SerialNumber, expiration time.Time) storj.SerialNumber {
	serialWithExp := storj.SerialNumber{}
	copy(serialWithExp[:], originalSerial[:])
	// make first 8 bytes of serial expiration so that it is stored as a partial serial
	binary.BigEndian.PutUint64(serialWithExp[0:8], uint64(expiration.Unix()))

	return serialWithExp
}