boolean hasReceivedNewVersionFromZooKeeper() {
        return currentVersion <= lastZooKeeperVersion;
    }
@Test
    void new_version_from_zk_predicate_initially_false() {
        final StateVersionTracker versionTracker = createWithMockedMetrics();
        assertFalse(versionTracker.hasReceivedNewVersionFromZooKeeper());
    }