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: ufs.go
    path of file: ./repos/minikube/third_party/go9p
    
    the code of the file until where you have to start completion: // Copyright 2009 The go9p Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package go9p

import (
	"io"
	"log"
	"os"
	"os/user"
	"path"
	"sort"
	"strconv"
	"syscall"
)


    
func lookup(uid string, group bool) (uint32, *Error) {
	if uid == "" {
		return NOUID, nil
	}
	usr, e := user.Lookup(uid)
	if e != nil {
		return NOUID, toError(e)
	}
	conv := usr.Uid
	if group {
		conv = usr.Gid
	}
	u, e := strconv.ParseUint(conv, 10, 32)
	if e != nil {
		return NOUID, toError(e)
	}
	return uint32(u), nil
}