assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'a', 'b', 'b');
  }

  @Test
  public void forGraph_breadthFirstIterable_iterableIsLazy() {
    RequestSavingGraph graph = new RequestSavingGraph(DIAMOND_GRAPH);
    Iterable<Character> result = Traverser.forGraph(graph).breadthFirst(charactersOf("ab"));