private void RemoveEmptySheets(SpreadsheetDocument spreadSheet, OpportunityReportDto data)
        {
            var sheetIdsToRemove = new List <string>();

            if (data.ReferralItems.Count == 0)
            {
                sheetIdsToRemove.Add(spreadSheet.GetSheetId(0));
            }

            if (data.ProvisionGapItems.Count == 0)
            {
                sheetIdsToRemove.Add(spreadSheet.GetSheetId(1));
            }

            foreach (var sheetId in sheetIdsToRemove)
            {
                spreadSheet.DeleteSheet(sheetId);
            }
        }