.inOrder();
  }

  private static class RequestSavingGraph implements SuccessorsFunction<Character> {
    private final SuccessorsFunction<Character> delegate;
    final Multiset<Character> requestedNodes = HashMultiset.create();

    RequestSavingGraph(SuccessorsFunction<Character> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override

        .inOrder();
  }

  private static class RequestSavingGraph implements SuccessorsFunction<Character> {
    private final SuccessorsFunction<Character> delegate;
    final Multiset<Character> requestedNodes = HashMultiset.create();

    RequestSavingGraph(SuccessorsFunction<Character> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override

 * @since 15.0
 * @deprecated Use {@link com.google.common.graph.Traverser} instead. All instance methods have
 *     their equivalent on the result of {@code Traverser.forTree(tree)} where {@code tree}
 *     implements {@code SuccessorsFunction}, which has a similar API as {@link #children} or can be
 *     the same lambda function as passed into {@link #using(Function)}.
 *     <p>This class is scheduled to be removed in October 2019.
 */

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

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

 * @param <E> Edge parameter type
 * @since 20.0
 */
@Beta
@DoNotMock("Use NetworkBuilder to create a real instance")
@ElementTypesAreNonnullByDefault
public interface Network<N, E> extends SuccessorsFunction<N>, PredecessorsFunction<N> {
  //
  // Network-level accessors
  //

  /** Returns all nodes in this network, in the order specified by {@link #nodeOrder()}. */
  Set<N> nodes();

 * @param <E> Edge parameter type
 * @since 20.0
 */
@Beta
@DoNotMock("Use NetworkBuilder to create a real instance")
@ElementTypesAreNonnullByDefault
public interface Network<N, E> extends SuccessorsFunction<N>, PredecessorsFunction<N> {
  //
  // Network-level accessors
  //

  /** Returns all nodes in this network, in the order specified by {@link #nodeOrder()}. */
  Set<N> nodes();