@Test
public void writeCell() throws Exception {

    final Workbook workbook = new XSSFWorkbook();
    final ExcelSheet excelSheet = new MockExcelSheet(workbook);
    final Sheet sheet = workbook.createSheet("sheet");
    final Row row = sheet.createRow(0);
    excelSheet.writeCell(null, row, 0);
    excelSheet.writeCell(Boolean.TRUE, row, 1);
    excelSheet.writeCell("text", row, 2);
    excelSheet.writeCell(1, row, 3);
    Assert.assertEquals(CellType.BLANK, row.getCell(0).getCellType());
    Assert.assertEquals("Yes", row.getCell(1).getStringCellValue());
    Assert.assertEquals(CellType.STRING, row.getCell(2).getCellType());
    Assert.assertEquals(CellType.NUMERIC, row.getCell(3).getCellType());
}