@Subscribe
    public synchronized void renew(final ClusterStateEvent event) {
        contextManager.getStateContext().switchClusterState(event.getClusterState());
    }
@Test
    void assertRenewClusterState() {
        ClusterStateEvent mockClusterStateEvent = new ClusterStateEvent(ClusterState.READ_ONLY);
        subscriber.renew(mockClusterStateEvent);
        assertThat(contextManager.getStateContext().getClusterState(), is(ClusterState.READ_ONLY));
    }