public void testGetSeriesKey() {
        DefaultIntervalXYDataset d = createSampleDataset1();
        assertEquals("S1", d.getSeriesKey(0));
        assertEquals("S2", d.getSeriesKey(1));

        // check for series key out of bounds
        boolean pass = false;
        try {
            /*Comparable k =*/ d.getSeriesKey(-1);
        }
        catch (IllegalArgumentException e) {
            pass = true;
        }
        assertTrue(pass);

        pass = false;
        try {
            /*Comparable k =*/ d.getSeriesKey(2);
        }
        catch (IllegalArgumentException e) {
            pass = true;
        }
        assertTrue(pass);