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: jobobject.go
    path of file: ./repos/sealer/vendor/github.com/Microsoft/hcsshim/internal/jobobject
    
    the code of the file until where you have to start completion: package jobobject

import (
	"context"
	"errors"
	"fmt"
	"sync"
	"unsafe"

	"github.com/Microsoft/hcsshim/internal/queue"
	"github.com/Microsoft/hcsshim/internal/winapi"
	"golang.org/x/sys/windows"
)

// This fil
    
func (job *JobObject) Close() error {
	job.handleLock.Lock()
	defer job.handleLock.Unlock()

	if job.handle == 0 {
		return ErrAlreadyClosed
	}

	if err := windows.Close(job.handle); err != nil {
		return err
	}

	if job.mq != nil {
		job.mq.Close()
	}
	// Handles now invalid so if the map entry to receive notifications for this job still
	// exists remove it so we can stop receiving notifications.
	if _, ok := jobMap.Load(uintptr(job.handle)); ok {
		jobMap.Delete(uintptr(job.handle))
	}

	job.handle = 0
	return nil
}