@Test
public void screenToSeries_returnsSeriesCoords() {

    when(xyPlot.getBounds()).thenReturn(new RectRegion(-100, 100, -100, 100));
    XYCoords coords = graphWidget.screenToSeries(new PointF(0, 0));
    assertEquals(-100, coords.x.intValue());
    assertEquals(100, coords.y.intValue());
    coords = graphWidget.screenToSeries(new PointF(10, 100));
    assertEquals(100, coords.x.intValue());
    assertEquals(-100, coords.y.intValue());
    coords = graphWidget.screenToSeries(new PointF(5, 50));
    assertEquals(0, coords.x.intValue());
    assertEquals(0, coords.y.intValue());
}