public void forTree_breadthFirstIterable_twoTrees() {
    assertEqualCharNodes(Traverser.forTree(TWO_TREES).breadthFirst(charactersOf("a")), "ab");
    assertEqualCharNodes(Traverser.forTree(TWO_TREES).breadthFirst(charactersOf("ca")), "cadb");
  }

  @Test
  public void forTree_breadthFirst_singleRoot() {
    Iterable<Character> result = Traverser.forTree(SINGLE_ROOT).breadthFirst('a');

    assertEqualCharNodes(result, "a");
  }

   * "/home/alice", ...]}
   *
   * @since 23.5
   */
  public static Traverser<File> fileTraverser() {
    return Traverser.forTree(FILE_TREE);
  }

  private static final SuccessorsFunction<File> FILE_TREE =
      file -> {
        // check isDirectory() just because it may be faster than listFiles() on a non-directory

   * "/home/alice", ...]}
   *
   * @since 23.5
   */
  public static Traverser<File> fileTraverser() {
    return Traverser.forTree(FILE_TREE);
  }

  private static final SuccessorsFunction<File> FILE_TREE =
      file -> {
        // check isDirectory() just because it may be faster than listFiles() on a non-directory

1F8B2..1F8FF  ; disallowed                             # NA   <reserved-1F8B2>..<reserved-1F8FF>
1F900..1F90B  ; valid                  ;      ; NV8    # 10.0 CIRCLED CROSS FORMEE WITH FOUR DOTS..DOWNWARD FACING NOTCHED HOOK WITH DOT
1F90C         ; valid                  ;      ; NV8    # 13.0 PINCHED FINGERS
1F90D..1F90F  ; valid                  ;      ; NV8    # 12.0 WHITE HEART..PINCHING HAND