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: load_dump.go
    path of file: ./repos/tidb/pkg/store/mockstore/unistore/lockstore
    
    the code of the file until where you have to start completion: // Copyright 2019-present PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicab
    
func (ls *MemStore) DumpToFile(fileName string, meta []byte) error {
	tmpFileName := fileName + ".tmp"
	f, err := os.OpenFile(tmpFileName, os.O_CREATE|os.O_TRUNC|os.O_RDWR, 0600)
	if err != nil {
		return errors.Trace(err)
	}
	writer := bufio.NewWriter(f)
	err = ls.writeItem(writer, meta)
	if err != nil {
		return err
	}
	cnt := 0
	it := ls.NewIterator()
	for it.SeekToFirst(); it.Valid(); it.Next() {
		err = ls.writeItem(writer, it.key)
		if err != nil {
			return errors.Trace(err)
		}
		err = ls.writeItem(writer, it.val)
		if err != nil {
			return errors.Trace(err)
		}
		cnt++
	}
	err = writer.Flush()
	if err != nil {
		return errors.Trace(err)
	}
	err = f.Sync()
	if err != nil {
		return errors.Trace(err)
	}
	err = f.Close()
	if err != nil {
		return errors.Trace(err)
	}
	log.Info("dumped lockstore", zap.Int("entries", cnt))
	return errors.Trace(os.Rename(tmpFileName, fileName))
}