*/
public void testIndexOf() {
XYSeries s1 = new XYSeries("S1");
XYSeries s2 = new XYSeries("S2");
XYSeriesCollection dataset = new XYSeriesCollection();
assertEquals(-1, dataset.indexOf(s1));
assertEquals(-1, dataset.indexOf(s2));
dataset.addSeries(s1);
assertEquals(0, dataset.indexOf(s1));
assertEquals(-1, dataset.indexOf(s2));