rootDir = Jimfs.newFileSystem(Configuration.unix()).getPath("/tmp");
    Files.createDirectory(rootDir);
  }

  @Override
  public void tearDown() throws IOException {
    rootDir.getFileSystem().close();
  }

  public void testFileTraverser_emptyDirectory() throws Exception {
    assertThat(MoreFiles.fileTraverser().breadthFirst(rootDir)).containsExactly(rootDir);
  }