### Question:
NodeService { public void update(String cluster, String path, String data, String creator) throws ShepherException { nodeBiz.update(cluster, path, data); Stat stat = nodeDAO.getStat(cluster, path, true); snapshotBiz.create(cluster, path, data, creator, Action.UPDATE, stat.getCtime(), ReviewStatus.ACCEPTED, stat.getVersion(), ReviewUtil.DEFAULT_REVIEWER); logger.info("Update node, cluster={}, path={}, operator={}", cluster, path, creator); }  List<String> getChildren(String cluster, String path); String getData(String cluster, String path); Stat getStat(String cluster, String path); Stat getStat(String cluster, String path, boolean returnNullIfPathNotExists); void create(String cluster, String path, String data, String creator); void create(String cluster, String path, String data, String creator, boolean createParents); void createEphemeral(String cluster, String path, String data, String creator); void updateWithPermission(String cluster, String path, String data, String creator); void update(String cluster, String path, String data, String creator); void delete(String cluster, String path, String creator);  }### Answer:
@Test public void testUpdate() throws Exception { nodeService.update("local_test", "/test", "", ""); }