public void persistInstanceWorkerId(final String instanceId, final int workerId) {
        repository.persistEphemeral(ComputeNode.getInstanceWorkerIdNodePath(instanceId), String.valueOf(workerId));
    }
@Test
    void assertPersistInstanceWorkerId() {
        InstanceMetaData instanceMetaData = new ProxyInstanceMetaData("foo_instance_id", 3307);
        final String instanceId = instanceMetaData.getId();
        new ComputeNodePersistService(repository).persistInstanceWorkerId(instanceId, 100);
        verify(repository).persistEphemeral(ComputeNode.getInstanceWorkerIdNodePath(instanceId), String.valueOf(100));
    }