s2.add(1);
assertTrue(s1.compareTo(s2) + "", s1.compareTo(s2) < 0);
assertTrue(s2.compareTo(s1) + "", s2.compareTo(s1) > 0);
assertTrue(s1.compareTo(s1) + "", s1.compareTo(s1) == 0);
assertTrue(s2.compareTo(s2) + "", s2.compareTo(s2) == 0);
}
@Test
public void testSubSignature() {