public ExternalSheet getExternalSheet(int externSheetIndex) {ExternalSheet sheet = _iBook.getExternalSheet(externSheetIndex);if (sheet == null) {int localSheetIndex = convertFromExternSheetIndex(externSheetIndex);if (localSheetIndex == -1) {return null;}if (localSheetIndex == -2) {return null;}String sheetName = getSheetName(localSheetIndex);int lastLocalSheetIndex = _iBook.getLastSheetIndexFromExternSheetIndex(externSheetIndex);if (lastLocalSheetIndex == localSheetIndex) {sheet = new ExternalSheet(null, sheetName);} else {String lastSheetName = getSheetName(lastLocalSheetIndex);sheet = new ExternalSheetRange(null, sheetName, lastSheetName);}}return sheet;}

public ExternalSheet GetExternalSheet(int externSheetIndex){ExternalSheet sheet = _iBook.GetExternalSheet(externSheetIndex);if (sheet == null){int localSheetIndex = ConvertFromExternSheetIndex(externSheetIndex);if (localSheetIndex == -1){return null;}if (localSheetIndex == -2){return null;}String sheetName = GetSheetName(localSheetIndex);int lastLocalSheetIndex = _iBook.GetLastSheetIndexFromExternSheetIndex(externSheetIndex);if (lastLocalSheetIndex == localSheetIndex){sheet = new ExternalSheet(null, sheetName);}else{String lastSheetName = GetSheetName(lastLocalSheetIndex);sheet = new ExternalSheetRange(null, sheetName, lastSheetName);}}return sheet;}
