@Test
public void createWorkbook() throws Exception {

    final ExcelChart excelChart = new ExcelChartDefault("line chart", ChartType.line, CATEGORIES, VALUES);
    excelChart.configureSeriesTitle(Arrays.asList("foo", "bar"));
    final Workbook workbook = excelChart.createWorkbook();
    Assert.assertNotNull(workbook);
    final Sheet sheet = workbook.getSheet(ChartType.line.toString());
    Assert.assertNotNull(sheet);
    final XSSFDrawing drawing = (XSSFDrawing) sheet.getDrawingPatriarch();
    final List<XSSFChart> charts = drawing.getCharts();
    Assert.assertEquals("number of charts", 1, charts.size());
    final XSSFChart chart = charts.get(0);
    Assert.assertEquals("chart title", "line chart", chart.getTitleText().getString());
    final CTChart ctChart = chart.getCTChart();
    Assert.assertEquals("We should not have any area chart", 0, ctChart.getPlotArea().getAreaChartArray().length);
    Assert.assertEquals("Check if we have 1 line chart", 1, ctChart.getPlotArea().getLineChartArray().length);
    Assert.assertEquals("Check that we have a legend and that it's position is bottom", STLegendPos.B,
            ctChart.getLegend().getLegendPos().getVal());
    // check the actual chart data
    final CTLineChart ctLineChart = ctChart.getPlotArea().getLineChartArray()[0];
    final CTLineSer[] ctLineSer = ctLineChart.getSerArray();
    Assert.assertEquals("Check number of CTLineSer", 2, ctLineSer.length);
    Assert.assertEquals("check first series title", "foo", ctLineSer[0].getTx().getV());
    Assert.assertEquals("check second series title", "bar", ctLineSer[1].getTx().getV());
    final CTAxDataSource cat1 = ctLineSer[0].getCat();
    Assert.assertEquals("check first category", "cat 1", cat1.getStrRef().getStrCache().getPtArray()[0].getV());
    Assert.assertEquals("check last category", "cat 5", cat1.getStrRef().getStrCache().getPtArray()[4].getV());
    final CTAxDataSource cat2 = ctLineSer[1].getCat();
    Assert.assertEquals("check first category", "cat 1", cat2.getStrRef().getStrCache().getPtArray()[0].getV());
    Assert.assertEquals("check last category", "cat 5", cat2.getStrRef().getStrCache().getPtArray()[4].getV());
    final CTNumDataSource val1 = ctLineSer[0].getVal();
    Assert.assertEquals("check first value", "5.0", val1.getNumRef().getNumCache().getPtArray()[0].getV());
    Assert.assertEquals("check last value", "6.0", val1.getNumRef().getNumCache().getPtArray()[4].getV());
    final CTNumDataSource val2 = ctLineSer[1].getVal();
    Assert.assertEquals("check first value", "20.0", val2.getNumRef().getNumCache().getPtArray()[0].getV());
    Assert.assertEquals("check last value", "14.0", val2.getNumRef().getNumCache().getPtArray()[4].getV());
    final List<? extends XSSFChartAxis> axis = chart.getAxis();
    Assert.assertEquals("number of axis", 2, axis.size());
    Assert.assertTrue("category axis", axis.get(0) instanceof XSSFCategoryAxis);
    Assert.assertTrue("value axis", axis.get(1) instanceof XSSFValueAxis);
}