@Test public void testMutate() { StopWatch s1 = new StopWatch(5, 59, 300); StopWatch s2 = new StopWatch(5, 59, 300); StopWatch.setMutate(false); s1.add(1000); s1.setMilliseconds(100); s1.setSeconds(50); s1.setMinutes(2); s1.add(s2); assertTrue(s1.equals(s2)); }