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: pageant_windows.go
    path of file: ./repos/lazygit/vendor/github.com/xanzy/ssh-agent
    
    the code of the file until where you have to start completion: //
// Copyright (c) 2014 David Mzareulyan
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this software
// and associated documentation files (the "Software"), to deal in the Software without restriction,
// including without limitation the rights to use, copy, modify, merge, publish, distribute,
// sublicense, and/or sell copies of the Software, and to permit persons to whom the Software
// is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or substantial
// portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WA
    
func query(msg []byte) ([]byte, error) {
	if len(msg) > MaxMessageLen {
		return nil, ErrMessageTooLong
	}

	msgLen := binary.BigEndian.Uint32(msg[:4])
	if len(msg) != int(msgLen)+4 {
		return nil, ErrInvalidMessageFormat
	}

	lock.Lock()
	defer lock.Unlock()

	paWin := pageantWindow()

	if paWin == 0 {
		return nil, ErrPageantNotFound
	}

	thID, _, _ := winGetCurrentThreadID()
	mapName := fmt.Sprintf("PageantRequest%08x", thID)
	pMapName, _ := syscall.UTF16PtrFromString(mapName)

	mmap, err := syscall.CreateFileMapping(syscall.InvalidHandle, nil, syscall.PAGE_READWRITE, 0, MaxMessageLen+4, pMapName)
	if err != nil {
		return nil, err
	}
	defer syscall.CloseHandle(mmap)

	ptr, err := syscall.MapViewOfFile(mmap, syscall.FILE_MAP_WRITE, 0, 0, 0)
	if err != nil {
		return nil, err
	}
	defer syscall.UnmapViewOfFile(ptr)

	mmSlice := (*(*[MaxMessageLen]byte)(unsafe.Pointer(ptr)))[:]

	copy(mmSlice, msg)

	mapNameBytesZ := append([]byte(mapName), 0)

	cds := copyData{
		dwData: agentCopydataID,
		cbData: uint32(len(mapNameBytesZ)),
		lpData: unsafe.Pointer(&(mapNameBytesZ[0])),
	}

	resp, _, _ := winSendMessage(paWin, wmCopydata, 0, uintptr(unsafe.Pointer(&cds)))

	if resp == 0 {
		return nil, ErrSendMessage
	}

	respLen := binary.BigEndian.Uint32(mmSlice[:4])
	if respLen > MaxMessageLen-4 {
		return nil, ErrResponseTooLong
	}

	respData := make([]byte, respLen+4)
	copy(respData, mmSlice)

	return respData, nil
}