@Override
    public boolean overlap(final Window other) {
        if (getClass() != other.getClass()) {
            throw new IllegalArgumentException("Cannot compare windows of different type. Other window has type "
                + other.getClass() + ".");
        }
        return true;
    }
@Test
    public void shouldAlwaysOverlap() {
        assertTrue(window.overlap(new UnlimitedWindow(start - 1)));
        assertTrue(window.overlap(new UnlimitedWindow(start)));
        assertTrue(window.overlap(new UnlimitedWindow(start + 1)));
    }