public void Clear()
        {
            sheet.RemoveRange(RangeHelper.GetEntireCol(sheet, 1));
            sheet.RemoveRange(RangeHelper.GetEntireCol(sheet, 1));
            //.Delete(XlDeleteShiftDirection.xlShiftToLeft);

            for (int i = 1; i < startRowIndex; i++)
            {
                sheet.RemoveRange(RangeHelper.GetEntireRow(sheet, 1));
                // .Delete(XlDeleteShiftDirection.xlShiftUp);
            }
        }