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: errors_windows.go
    path of file: ./repos/moby/vendor/github.com/moby/buildkit/frontend/dockerfile/instructions
    
    the code of the file until where you have to start completion: package instructions

import (
	"fmt"
	"path/filepath"
	"regexp"
	"strings"

	"github.com/pkg/errors"
)

func errNotJSO
    
func errNotJSON(command, original string) error {
	// For Windows users, give a hint if it looks like it might contain
	// a path which hasn't been escaped such as ["c:\windows\system32\prog.exe", "-param"],
	// as JSON must be escaped. Unfortunate...
	//
	// Specifically looking for quote-driveletter-colon-backslash, there's no
	// double backslash and a [] pair. No, this is not perfect, but it doesn't
	// have to be. It's simply a hint to make life a little easier.
	extra := ""
	original = filepath.FromSlash(strings.ToLower(strings.Replace(strings.ToLower(original), strings.ToLower(command)+" ", "", -1)))
	if len(regexp.MustCompile(`"[a-z]:\\.*`).FindStringSubmatch(original)) > 0 &&
		!strings.Contains(original, `\\`) &&
		strings.Contains(original, "[") &&
		strings.Contains(original, "]") {
		extra = fmt.Sprintf(`. It looks like '%s' includes a file path without an escaped back-slash. JSON requires back-slashes to be escaped such as ["c:\\path\\to\\file.exe", "/parameter"]`, original)
	}
	return errors.Errorf("%s requires the arguments to be in JSON form%s", command, extra)
}