@Test
    public void WhenConcurentChanges_ExpectOrderedTimeEvents() throws InterruptedException {
        // Lamport entity.clock synchronization test

        thread1_.start();
        thread2_.start();
        thread1_.join();
        thread2_.join();

        Assert.assertTrue("Lamport entity.clock failed at synchronization",
                timestampList_.size() == (events1_ + events2_));

        long previous = timestampList_.get(0);
        for (int i = 1; i < timestampList_.size(); i++) {
            long next = timestampList_.get(i);
            String msg1 = previous + " ?<=? " + next;
            Assert.assertTrue(msg1, previous <= next);
            previous = next;
        }
    }