private void ResponseExcelWorkBook(WfActivityMatrixResourceDescriptor activityMatrix, string fileName)
        {
            WorkBook workBook = WorkBook.CreateNew();

            workBook.Sheets.Clear();

            workBook.FillActivityMatrixResourceDescriptor(activityMatrix);

            Response.AppendExcelOpenXmlHeader(fileName);

            workBook.Save(Response.OutputStream);

            Response.End();
        }