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: identity.go
    path of file: ./repos/evcc/vehicle/mb
    
    the code of the file until where you have to start completion: package mb

import (
	"context"
	"fmt"
	"net/http"
	"net/http/cookiejar"
	"net/url"
	"strings"

	"github.com/evcc-io/evcc/util"
	"github.com/evcc-io/evcc/util/request"
	"github.com/samber/lo"
	"golang.org/x/net/publicsuffix"
	"golang.org/x/oauth2"
)

// https://github.com/TA2k/ioBroker.smart-eq

// https://id.mercedes-benz.com/.well-known/openid-configuration
const OAuthURI = "https://id.mercedes-benz.com"

type Identity struct {
	*request.Helper
	oc *oauth2.Config
	oauth2.TokenSource
}

// NewIdentity creates Mercedes Benz identity
func NewIdentity(log *util.Logger, oc *oauth2.Config) *Identity {
	return &Identity{
		Helper: request.NewHelper(log),
		oc:     oc,
	}
}

func (v *Identity) Login(user, password string) error {
	if v.Client.Jar == nil {
		v.Client.Jar, _ = cookiejar.New(&cookiejar.Options{
			PublicSuffixList: publicsuffix.List,
		})
	}

	var param request.InterceptResult
	v.Client.CheckRedirect, param = request.InterceptRedirect("resume", false)

	cv := oauth2.GenerateVerifier()

	state := lo.RandomString(16, lo.AlphanumericCharset)
	uri := v.oc.AuthCodeURL(state, oauth2.AccessTypeOffline, oauth2.S256ChallengeOption(cv))
	if _, err := v.Get(uri); err != nil {
		return err
	}

	resume, err := param()
	if err != nil {
		return err
	}

	v.Client.CheckRedirect = nil

	data := struct {
		Username   string `json:"username"`
		Password   string `json:"password,omitempty"`
		RememberMe bool   `json:"rememberMe,omitempty"`
	}{
		Username: user,
	}

	var res struct {
		Result, Token string
		Errors        []struct{ Key string }
	}

	uri = fmt.Sprintf("%s/ciam/auth/login/user", OAuthURI)
	req, err := request.New(http.MethodPost, uri, request.MarshalJSON(data), request.JSONEncoding)
	if err == nil {
		if err = v.DoJSON(req, &res); err != nil && len(res.Errors) > 0 {
			err = fmt.Errorf("%s: %w", res.Errors[0].Key, err)
		}
	}

	if err == nil {
		data.Password = password
		data.RememberMe = true

		uri = fmt.Sprintf("%s/ciam/auth/login/pass", OAuthURI)
		req, err = request.New(http.MethodPost, uri, request.MarshalJSON(data), request.JSONEncoding)
		if err == nil {
			if err = v.DoJSON(req, &res); err != nil && len(res.Errors) > 0 {
				err = fmt.Errorf("%s: %w", res.Errors[0].Key, err)
			}
		}
	}

	if err == nil && res.Token == "" && res.Result != "" {
		err = fmt.Errorf("missing token: %s", res
    
func (v *Identity) Login(user, password string) error {
	if v.Client.Jar == nil {
		v.Client.Jar, _ = cookiejar.New(&cookiejar.Options{
			PublicSuffixList: publicsuffix.List,
		})
	}

	var param request.InterceptResult
	v.Client.CheckRedirect, param = request.InterceptRedirect("resume", false)

	cv := oauth2.GenerateVerifier()

	state := lo.RandomString(16, lo.AlphanumericCharset)
	uri := v.oc.AuthCodeURL(state, oauth2.AccessTypeOffline, oauth2.S256ChallengeOption(cv))
	if _, err := v.Get(uri); err != nil {
		return err
	}

	resume, err := param()
	if err != nil {
		return err
	}

	v.Client.CheckRedirect = nil

	data := struct {
		Username   string `json:"username"`
		Password   string `json:"password,omitempty"`
		RememberMe bool   `json:"rememberMe,omitempty"`
	}{
		Username: user,
	}

	var res struct {
		Result, Token string
		Errors        []struct{ Key string }
	}

	uri = fmt.Sprintf("%s/ciam/auth/login/user", OAuthURI)
	req, err := request.New(http.MethodPost, uri, request.MarshalJSON(data), request.JSONEncoding)
	if err == nil {
		if err = v.DoJSON(req, &res); err != nil && len(res.Errors) > 0 {
			err = fmt.Errorf("%s: %w", res.Errors[0].Key, err)
		}
	}

	if err == nil {
		data.Password = password
		data.RememberMe = true

		uri = fmt.Sprintf("%s/ciam/auth/login/pass", OAuthURI)
		req, err = request.New(http.MethodPost, uri, request.MarshalJSON(data), request.JSONEncoding)
		if err == nil {
			if err = v.DoJSON(req, &res); err != nil && len(res.Errors) > 0 {
				err = fmt.Errorf("%s: %w", res.Errors[0].Key, err)
			}
		}
	}

	if err == nil && res.Token == "" && res.Result != "" {
		err = fmt.Errorf("missing token: %s", res.Result)
	}

	var code string
	if err == nil {
		params := url.Values{
			"token": {res.Token},
		}

		var param request.InterceptResult
		v.Client.CheckRedirect, param = request.InterceptRedirect("code", true)

		uri := OAuthURI + resume
		if _, err = v.Post(uri, request.FormContent, strings.NewReader(params.Encode())); err == nil {
			code, err = param()
		}

		v.Client.CheckRedirect = nil
	}

	var token *oauth2.Token
	if err == nil {
		ctx, cancel := context.WithTimeout(
			context.WithValue(context.Background(), oauth2.HTTPClient, v.Client),
			request.Timeout)
		defer cancel()

		token, err = v.oc.Exchange(ctx, code, oauth2.VerifierOption(cv))
	}

	if err == nil {
		v.TokenSource = v.oc.TokenSource(context.Background(), token)
	}

	return err
}