File file = newDir("some-dir");

    assertThat(Files.fileTraverser().breadthFirst(rootDir)).containsExactly(rootDir, file);
  }

  public void testFileTraverser_multipleFilesAndDirectories() throws Exception {
    File fileA = newFile("file-a");
    File fileB = newFile("file-b");
    File dir1 = newDir("dir-1");
    File dir2 = newDir("dir-2");