@Override
    public boolean compareAndSetSequence(long expect, long update) {
        return sequence.compareAndSet(expect, update);
    }
@Test
    public void testCompareAndSetSequence() {
        sequencer.compareAndSetSequence(23, 42);
        assertEquals(0, sequencer.getSequence());

        sequencer.compareAndSetSequence(0, 42);
        assertEquals(42, sequencer.getSequence());
    }