public FileResult UniVariateChartByState(string chartSize, string chartType, int country_id, int test_id, int?category_id, int?question_id)
{
Test test = new TestsServices().GetById(test_id);
ChartDetails cd = new ChartDetails(chartSize, chartType, false, this.GetChartDetails(12, 13), 2,
test.GetAvgAndMedByStates(null, null, country_id), test_id);
MemoryStream ms = new MemoryStream();
cd.chart.SaveImage(ms);
return(new FileContentResult(ms.GetBuffer(), @"image/png"));
}