@Override
                  protected Set<String> create(String[] elements) {
                    return new StandardImplForwardingNavigableSet<>(
                        new SafeTreeSet<String>(asList(elements)));
                  }

                  @Override
                  public List<String> order(List<String> insertionOrder) {

    }
  }

  private static class MutateTask implements Callable<int[]> {
    private final ConcurrentHashMultiset<String> multiset;
    private final ImmutableList<String> keys;
    private final Random random = new Random();

    private MutateTask(ConcurrentHashMultiset<String> multiset, ImmutableList<String> keys) {
      this.multiset = multiset;
      this.keys = keys;
    }

    @Override

    @Override
    public String asTableDbName() {
        return asEsIndexType();
    }

    @Override
    protected String asEsIndex() {
        return "fess_log.favorite_log";
    }

    @Override
    public String asEsIndexType() {
        return "favorite_log";
    }

    @Override
    public String asEsSearchType() {
        return "favorite_log";
    }

    @Override
    public String asTableDbName() {
        return asEsIndexType();
    }

    @Override
    protected String asEsIndex() {
        return "fess_user.role";
    }

    @Override
    public String asEsIndexType() {
        return "role";
    }

    @Override
    public String asEsSearchType() {
        return "role";
    }

    @Override

    @Override
    public String asTableDbName() {
        return asEsIndexType();
    }

    @Override
    protected String asEsIndex() {
        return "fess_config.bad_word";
    }

    @Override
    public String asEsIndexType() {
        return "bad_word";
    }

    @Override
    public String asEsSearchType() {
        return "bad_word";
    }

    @Override
    public String asTableDbName() {
        return asEsIndexType();
    }

    @Override
    protected String asEsIndex() {
        return "fess_config.crawling_info_param";
    }

    @Override
    public String asEsIndexType() {
        return "crawling_info_param";
    }

    @Override
    public String asEsSearchType() {
        return "crawling_info_param";
    }

    @Override
    public String asTableDbName() {
        return asEsIndexType();
    }

    @Override
    protected String asEsIndex() {
        return "fess_config.path_mapping";
    }

    @Override
    public String asEsIndexType() {
        return "path_mapping";
    }

    @Override
    public String asEsSearchType() {
        return "path_mapping";
    }

  virtual const FunctionDef* FindFunctionDef(const string& name) const = 0;

  // Find and return a function record added by its name.
  virtual core::RefCountPtr<FunctionRecord> FindRecord(
      const string& name) const = 0;

  // Return the ParsedName of Host CPU device.
  virtual const DeviceNameUtils::ParsedName& HostCPUParsedName() const = 0;
  virtual const string& HostCPUName() const = 0;

     */
    @Test
    public void test() throws Exception {
        final List<String> list = newArrayList();
        list.add("aaa");
        list.add("bbb");
        list.add("ccc");

        final IndexedIterator<String> it = new IndexedIterator<String>(list.iterator());

        assertThat(it.hasNext(), is(true));

        final Indexed<String> indexed1 = it.next();
        assertThat(indexed1.getIndex(), is(0));

        return path.toString();
    }

    public String pathOfRemoteRepositoryMetadata(ArtifactMetadata metadata) {
        return pathOfRepositoryMetadata(metadata, metadata.getRemoteFilename());
    }

    private String formatAsDirectory(String directory) {
        return directory.replace(GROUP_SEPARATOR, PATH_SEPARATOR);
    }

    @Override
    public String toString() {
        return getId();
    }