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: sdk.go
    path of file: ./repos/oauth2/google
    
    the code of the file until where you have to start completion: // Copyright 2015 The Go 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 google

import (
	"bufio"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"
    
func guessUnixHomeDir() string {
	// Prefer $HOME over user.Current due to glibc bug: golang.org/issue/13470
	if v := os.Getenv("HOME"); v != "" {
		return v
	}
	// Else, fall back to user.Current:
	if u, err := user.Current(); err == nil {
		return u.HomeDir
	}
	return ""
}