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: model.go
    path of file: ./repos/grafana/pkg/services/auth/authimpl
    
    the code of the file until where you have to start completion: package authimpl

import (
	"fmt"

	"github.com/grafana/grafana/pkg/services/auth"
)

type userAuthToken struct {
	Id            int64
	UserId        int64
	AuthToken     string
	PrevAuthToken string
	UserAgent     strin
    
func (uat *userAuthToken) fromUserToken(ut *auth.UserToken) error {
	if uat == nil {
		return fmt.Errorf("needs pointer to userAuthToken struct")
	}

	uat.Id = ut.Id
	uat.UserId = ut.UserId
	uat.AuthToken = ut.AuthToken
	uat.PrevAuthToken = ut.PrevAuthToken
	uat.UserAgent = ut.UserAgent
	uat.ClientIp = ut.ClientIp
	uat.AuthTokenSeen = ut.AuthTokenSeen
	uat.SeenAt = ut.SeenAt
	uat.RotatedAt = ut.RotatedAt
	uat.CreatedAt = ut.CreatedAt
	uat.UpdatedAt = ut.UpdatedAt
	uat.RevokedAt = ut.RevokedAt
	uat.UnhashedToken = ut.UnhashedToken

	return nil
}