### Question:
StackedXYAreaRenderer2 extends XYAreaRenderer2 implements Cloneable, PublicCloneable, Serializable { @Override public Range findRangeBounds(XYDataset dataset) { if (dataset == null) { return null; } double min = Double.POSITIVE_INFINITY; double max = Double.NEGATIVE_INFINITY; TableXYDataset d = (TableXYDataset) dataset; int itemCount = d.getItemCount(); for (int i = 0; i < itemCount; i++) { double[] stackValues = getStackValues((TableXYDataset) dataset, d.getSeriesCount(), i); min = Math.min(min, stackValues[0]); max = Math.max(max, stackValues[1]); } if (min == Double.POSITIVE_INFINITY) { return null; } return new Range(min, max); } StackedXYAreaRenderer2();  StackedXYAreaRenderer2(XYToolTipGenerator labelGenerator,
                                  XYURLGenerator urlGenerator); boolean getRoundXCoordinates(); void setRoundXCoordinates(boolean round); @Override Range findRangeBounds(XYDataset dataset); @Override int getPassCount(); @Override void drawItem(Graphics2D g2,
                         XYItemRendererState state,
                         Rectangle2D dataArea,
                         PlotRenderingInfo info,
                         XYPlot plot,
                         ValueAxis domainAxis,
                         ValueAxis rangeAxis,
                         XYDataset dataset,
                         int series,
                         int item,
                         CrosshairState crosshairState,
                         int pass); @Override boolean equals(Object obj); @Override Object clone();  }### Answer:
@Test public void testFindRangeBounds() { TableXYDataset dataset = RendererXYPackageTests.createTestTableXYDataset(); JFreeChart chart = ChartFactory.createStackedXYAreaChart( "Test Chart", "X", "Y", dataset); XYPlot plot = (XYPlot) chart.getPlot(); StackedXYAreaRenderer2 renderer = new StackedXYAreaRenderer2(); plot.setRenderer(renderer); NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis(); Range bounds = rangeAxis.getRange(); assertTrue(bounds.contains(6.0)); assertTrue(bounds.contains(8.0)); assertNull(renderer.findRangeBounds(null)); assertNull(renderer.findRangeBounds(new DefaultTableXYDataset())); }