### Question:
CategoryStepRenderer extends AbstractCategoryItemRenderer implements Cloneable, PublicCloneable, Serializable { @Override public LegendItem getLegendItem(int datasetIndex, int series) { CategoryPlot p = getPlot(); if (p == null) { return null; } if (!isSeriesVisible(series) || !isSeriesVisibleInLegend(series)) { return null; } CategoryDataset dataset = p.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); LegendItem item = new LegendItem(label, description, toolTipText, urlText, shape, paint); item.setLabelFont(lookupLegendTextFont(series)); Paint labelPaint = lookupLegendTextPaint(series); if (labelPaint != null) { item.setLabelPaint(labelPaint); } item.setSeriesKey(dataset.getRowKey(series)); item.setSeriesIndex(series); item.setDataset(dataset); item.setDatasetIndex(datasetIndex); return item; } CategoryStepRenderer();  CategoryStepRenderer(boolean stagger); boolean getStagger(); void setStagger(boolean shouldStagger); @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); static final int STAGGER_WIDTH; }### 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"); CategoryStepRenderer r = new CategoryStepRenderer(); 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()); }