public IRestResponse Batch(string listUrl, ListItems items, string action) { var body = items.Serialize(); var client = new RestClient(listUrl); var request = new RestRequest("batch", Method.POST); request.AddQueryParameter("type", action); request.AddHeader("Accept", "application/xml"); request.AddHeader("Authorization", "OAuth " + this.accessToken.Token); request.AddParameter("application/xml", body, ParameterType.RequestBody); return(client.Execute(request)); }