### Question:
AreaRenderer extends AbstractCategoryItemRenderer implements Cloneable, PublicCloneable, Serializable { @Override public LegendItem getLegendItem(int datasetIndex, int series) { CategoryPlot cp = getPlot(); if (cp == null) { return null; } if (!isSeriesVisible(series) || !isSeriesVisibleInLegend(series)) { return null; } CategoryDataset dataset = cp.getDataset(datasetIndex); String label = getLegendItemLabelGenerator().generateLabel(dataset, series); String description = label; String toolTipText = null; if (getLegendItemToolTipGenerator() != null) { toolTipText = getLegendItemToolTipGenerator().generateLabel( dataset, series); } String urlText = null; if (getLegendItemURLGenerator() != null) { urlText = getLegendItemURLGenerator().generateLabel(dataset, series); } Shape shape = lookupLegendShape(series); Paint paint = lookupSeriesPaint(series); Paint outlinePaint = lookupSeriesOutlinePaint(series); Stroke outlineStroke = lookupSeriesOutlineStroke(series); LegendItem result = new LegendItem(label, description, toolTipText, urlText, shape, paint, outlineStroke, outlinePaint); result.setLabelFont(lookupLegendTextFont(series)); Paint labelPaint = lookupLegendTextPaint(series); if (labelPaint != null) { result.setLabelPaint(labelPaint); } result.setDataset(dataset); result.setDatasetIndex(datasetIndex); result.setSeriesKey(dataset.getRowKey(series)); result.setSeriesIndex(series); return result; } AreaRenderer(); AreaRendererEndType getEndType(); void setEndType(AreaRendererEndType type); @Override LegendItem getLegendItem(int datasetIndex, int series); @Override void drawItem(Graphics2D g2, CategoryItemRendererState state,
            Rectangle2D dataArea, CategoryPlot plot, CategoryAxis domainAxis,
            ValueAxis rangeAxis, CategoryDataset dataset, int row, int column,
            int pass); @Override boolean equals(Object obj); @Override Object clone();  }### Answer:
@Test public void testGetLegendItemSeriesIndex() { DefaultCategoryDataset dataset0 = new DefaultCategoryDataset(); dataset0.addValue(21.0, "R1", "C1"); dataset0.addValue(22.0, "R2", "C1"); DefaultCategoryDataset dataset1 = new DefaultCategoryDataset(); dataset1.addValue(23.0, "R3", "C1"); dataset1.addValue(24.0, "R4", "C1"); dataset1.addValue(25.0, "R5", "C1"); AreaRenderer r = new AreaRenderer(); CategoryPlot plot = new CategoryPlot(dataset0, new CategoryAxis("x"), new NumberAxis("y"), r); plot.setDataset(1, dataset1); new JFreeChart(plot); LegendItem li = r.getLegendItem(1, 2); assertEquals("R5", li.getLabel()); assertEquals(1, li.getDatasetIndex()); assertEquals(2, li.getSeriesIndex()); }