@Test
public void testGetPixelLocation_cachedPoint() {

    final Point2D.Double pixelLocation = new Point2D.Double();
    assertTrue(locator.getPixelLocation(10, 20, pixelLocation));
    assertEquals(0.0, pixelLocation.getX(), 1e-8);
    assertEquals(0.0, pixelLocation.getY(), 1e-8);
    assertTrue(locator.getPixelLocation(10, 20, pixelLocation));
    assertEquals(0.0, pixelLocation.getX(), 1e-8);
    assertEquals(0.0, pixelLocation.getY(), 1e-8);
    // just an indirect check - at least that part of the cache-handling code is covered. Hard to check, though tb 2015-05-16
}