Tests reading a file containing this ptg.
HSSFWorkbook workbook = loadWorkbook("IntersectionPtg.xls");
HSSFCell cell = workbook.getSheetAt(0).getRow(4).getCell((short) 2);
assertEquals("Wrong cell value", 5.0, cell.getNumericCellValue(), 0.0);
assertEquals("Wrong cell formula", "SUM(A1:B2 B2:C3)", cell.getCellFormula());