public void testHashCode() {
        SegmentedTimeline l1 = new SegmentedTimeline(1000, 5, 2);
        SegmentedTimeline l2 = new SegmentedTimeline(1000, 5, 2);
        assertTrue(l1.equals(l2));
        int h1 = l1.hashCode();
        int h2 = l2.hashCode();
        assertEquals(h1, h2);