@SuppressWarnings("unchecked")
    public Collection<String> loadInstanceLabels(final String instanceId) {
        String yamlContent = repository.query(ComputeNode.getInstanceLabelsNodePath(instanceId));
        return Strings.isNullOrEmpty(yamlContent) ? new LinkedList<>() : YamlEngine.unmarshal(yamlContent, Collection.class);
    }
@Test
    void assertLoadInstanceLabels() {
        InstanceMetaData instanceMetaData = new ProxyInstanceMetaData("foo_instance_id", 3307);
        final String instanceId = instanceMetaData.getId();
        new ComputeNodePersistService(repository).loadInstanceLabels(instanceId);
        verify(repository).query(ComputeNode.getInstanceLabelsNodePath(instanceId));
    }