*/
  public static <N> MutableGraph<N> inducedSubgraph(Graph<N> graph, Iterable<? extends N> nodes) {
    MutableGraph<N> subgraph =
        (nodes instanceof Collection)
            ? GraphBuilder.from(graph).expectedNodeCount(((Collection) nodes).size()).build()
            : GraphBuilder.from(graph).build();
    for (N node : nodes) {
      subgraph.addNode(node);
    }
    for (N node : subgraph.nodes()) {

        .isEqualTo(ImmutableSet.of(E12, E12_A, E21));
  }

  @Test
  public void createDirected_expectedNodeCount() {
    MutableNetwork<Integer, String> directedGraph =
        NetworkBuilder.directed().expectedNodeCount(NODE_COUNT).build();
    assertThat(directedGraph.addEdge(N1, N2, E12)).isTrue();
    assertThat(directedGraph.edgesConnecting(N1, N2)).isEqualTo(ImmutableSet.of(E12));