internal static HttpRequest GetLoginRequest(ZuoraConfig config)
        {
            HttpRequest request = new HttpRequest
            {
                Url    = config.InstanceUrl + config.SoapUrl,
                Body   = SoapCommands.Login(config.Username, config.Password),
                Method = RequestType.POST,
            };

            request.Headers.Add("SOAPAction", "login");

            return(request);
        }