Iterable<Character> result = Traverser.forGraph(TWO_TREES).breadthFirst('a');

    assertEqualCharNodes(result, "ab");
  }

  @Test
  public void forGraph_breadthFirstIterable_twoTrees() {
    assertEqualCharNodes(Traverser.forGraph(TWO_TREES).breadthFirst(charactersOf("a")), "ab");
    assertEqualCharNodes(Traverser.forGraph(TWO_TREES).breadthFirst(charactersOf("ac")), "acbd");
  }

  @Test

    Iterable<Character> result = Traverser.forGraph(TWO_TREES).breadthFirst('a');

    assertEqualCharNodes(result, "ab");
  }

  @Test
  public void forGraph_breadthFirstIterable_twoTrees() {
    assertEqualCharNodes(Traverser.forGraph(TWO_TREES).breadthFirst(charactersOf("a")), "ab");
    assertEqualCharNodes(Traverser.forGraph(TWO_TREES).breadthFirst(charactersOf("ac")), "acbd");
  }

  @Test

   */
  public static <N> ImmutableSet<N> reachableNodes(Graph<N> graph, N node) {
    checkArgument(graph.nodes().contains(node), NODE_NOT_IN_GRAPH, node);
    return ImmutableSet.copyOf(Traverser.forGraph(graph).breadthFirst(node));
  }

  // Graph mutation methods

  // Graph view methods

  /**
   * Returns a view of {@code graph} with the direction (if any) of every edge reversed. All other

   */
  public static <N> ImmutableSet<N> reachableNodes(Graph<N> graph, N node) {
    checkArgument(graph.nodes().contains(node), NODE_NOT_IN_GRAPH, node);
    return ImmutableSet.copyOf(Traverser.forGraph(graph).breadthFirst(node));
  }

  // Graph mutation methods

  // Graph view methods

  /**
   * Returns a view of {@code graph} with the direction (if any) of every edge reversed. All other