@Test
public void testDrawSeries_withInterpolation() throws Exception {

    LineAndPointRenderer renderer = spy(new LineAndPointRenderer(xyPlot));
    LineAndPointFormatter formatter = new LineAndPointFormatter();
    formatter.setInterpolationParams(
            new CatmullRomInterpolator.Params(10, CatmullRomInterpolator.Type.Centripetal));
    XYSeries series = new SimpleXYSeries(SimpleXYSeries.ArrayFormat.Y_VALS_ONLY, "Series1", 1, 2, 3);
    renderer.drawSeries(canvas, plotArea, series, formatter);
}