/** Check that setting a tool tip generator for a series does override the default generator. */
 public void testSetSeriesToolTipGenerator() {
   XYPlot plot = (XYPlot) this.chart.getPlot();
   XYItemRenderer renderer = plot.getRenderer();
   StandardXYToolTipGenerator tt = new StandardXYToolTipGenerator();
   renderer.setSeriesToolTipGenerator(0, tt);
   XYToolTipGenerator tt2 = renderer.getToolTipGenerator(0, 0);
   assertTrue(tt2 == tt);
 }