public DataSourceResult GetTimeRateList([ModelBinder(typeof(WebApiDataSourceRequestModelBinder))]DataSourceRequest request, string id, string curr)
 {
    id = id ?? "";
    curr = curr ?? "";
    using (var ctx = new ModelerContext())
    {
       IEnumerable<ListTimeRateVM> rates = ctx.getTimeRateList(id, curr);
       return rates.ToDataSourceResult(request);
    }
 }