// Update any formulas on this sheet that point to
// rows which have been moved
int sheetIndex = _workbook.getSheetIndex(this);
String sheetName = _workbook.getSheetName(sheetIndex);
short externSheetIndex = _book.checkExternSheet(sheetIndex);
FormulaShifter shifter = FormulaShifter.createForRowShift(
externSheetIndex, sheetName, startRow, endRow, n);
_sheet.updateFormulasAfterCellShift(shifter, externSheetIndex);
int nSheets = _workbook.getNumberOfSheets();
for (int i = 0; i < nSheets; i++) {