public static GridBoundColumnBuilder <TModel> Sum <TModel>(this GridBoundColumnBuilder <TModel> builder, string formatString = null) where TModel : class
        {
            string sum = string.Format("#= sum == 0 ? '0' : kendo.format('{0}', sum) #", formatString ?? FormatStrings.TelerikGridSumFormat);

            return(builder
                   .AlignRight()
                   .AggregateForKendo("sum")
                   .ClientFooterTemplate(string.Format("<div style='text-align: right;'>{0}</div>", sum)));
        }