text: public override String ToString(){StringBuilder sb = new StringBuilder();sb.Append(this.GetType().Name);sb.Append(" [");if (externalWorkbookNumber >= 0){sb.Append(" [");sb.Append("workbook=").Append(ExternalWorkbookNumber);sb.Append("] ");}sb.Append("sheet=").Append(SheetName);if (lastSheetName != null){sb.Append(" : ");sb.Append("sheet=").Append(lastSheetName);}sb.Append(" ! ");sb.Append(FormatReferenceAsString());sb.Append("]");return sb.ToString();}