Get auth needs to accept and return token as well as accesskey, secret key

I use GetAuth like this:

	auth, err := aws.GetAuth(_ServerAuth.AccessKey, _ServerAuth.SecretKey)
	if err != nil {
            log.Printf("something horrible happened here")
        }

in this scenario, I need GetAuth to accept and return the token in case I've had a temporary token already, I want to keep it,