newFile("dir-1/dir-2");

    assertThat(Iterables.limit(Files.fileTraverser().breadthFirst(rootDir), 3))
        .containsExactly(rootDir, fileA, dir1);
  }

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