}

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

  public static <N, E> MutableNetwork<N, E> copyOf(Network<N, E> network) {
    MutableNetwork<N, E> copy =
        NetworkBuilder.from(network)
            .expectedNodeCount(network.nodes().size())
            .expectedEdgeCount(network.edges().size())
            .build();
    for (N node : network.nodes()) {
      copy.addNode(node);
    }
    for (E edge : network.edges()) {

  public static <N, E> MutableNetwork<N, E> copyOf(Network<N, E> network) {
    MutableNetwork<N, E> copy =
        NetworkBuilder.from(network)
            .expectedNodeCount(network.nodes().size())
            .expectedEdgeCount(network.edges().size())
            .build();
    for (N node : network.nodes()) {
      copy.addNode(node);
    }
    for (E edge : network.edges()) {