### Question:
IntervalBarRenderer extends BarRenderer { @Override public Range findRangeBounds(CategoryDataset dataset) { return findRangeBounds(dataset, true); } IntervalBarRenderer(); @Override Range findRangeBounds(CategoryDataset dataset); @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);  }### Answer:
@Test public void testFindRangeBounds() { IntervalBarRenderer r = new IntervalBarRenderer(); assertNull(r.findRangeBounds(null)); DefaultIntervalCategoryDataset dataset = new DefaultIntervalCategoryDataset(new double[0][0], new double[0][0]); assertNull(r.findRangeBounds(dataset)); double[][] starts = new double[][] {{0.1, 0.2, 0.3}, {0.3, 0.4, 0.5}}; double[][] ends = new double[][] {{0.5, 0.6, 0.7}, {0.7, 0.8, 0.9}}; dataset = new DefaultIntervalCategoryDataset(starts, ends); assertEquals(new Range(0.0, 0.9), r.findRangeBounds(dataset)); r.setIncludeBaseInRange(false); assertEquals(new Range(0.1, 0.9), r.findRangeBounds(dataset)); r.setIncludeBaseInRange(true); r.setSeriesVisible(1, Boolean.FALSE); assertEquals(new Range(0.0, 0.7), r.findRangeBounds(dataset)); }