return GraphBuilder.directed()
        .allowsSelfLoops(allowsSelfLoops)
        .incidentEdgeOrder(incidentEdgeOrder)
        .build();
  }

  @Override
  final void addNode(Integer n) {
    graphAsMutableGraph.addNode(n);
  }

  @Override
  final void putEdge(Integer n1, Integer n2) {
    graphAsMutableGraph.putEdge(n1, n2);
  }

    return GraphBuilder.directed()
        .allowsSelfLoops(allowsSelfLoops)
        .incidentEdgeOrder(incidentEdgeOrder)
        .build();
  }

  @Override
  final void addNode(Integer n) {
    graphAsMutableGraph.addNode(n);
  }

  @Override
  final void putEdge(Integer n1, Integer n2) {
    graphAsMutableGraph.putEdge(n1, n2);
  }

    mutableNetwork.addNode("A");
    ImmutableNetwork<String, Integer> immutableNetwork = ImmutableNetwork.copyOf(mutableNetwork);

    assertThat(immutableNetwork.asGraph()).isInstanceOf(ImmutableGraph.class);
    assertThat(immutableNetwork).isNotInstanceOf(MutableNetwork.class);
    assertThat(immutableNetwork).isEqualTo(mutableNetwork);

    mutableNetwork.addNode("B");

@RunWith(JUnit4.class)
public class ImmutableValueGraphTest {

  @Test
  public void immutableValueGraph() {
    MutableValueGraph<String, Integer> mutableValueGraph = ValueGraphBuilder.directed().build();
    mutableValueGraph.addNode("A");
    ImmutableValueGraph<String, Integer> immutableValueGraph =
        ImmutableValueGraph.copyOf(mutableValueGraph);

    assertThat(immutableValueGraph.asGraph()).isInstanceOf(ImmutableGraph.class);

    }
    throw new IllegalStateException("Unexpected edge type: " + edgeType);
  }

  @Test
  public void equivalent_nodeSetsDiffer() {
    graph.addNode(N1);

    MutableGraph<Integer> g2 = createGraph(edgeType);
    g2.addNode(N2);

    assertThat(graph).isNotEqualTo(g2);
  }

  // Node/edge sets are the same, but node/edge connections differ due to edge type.
  @Test

    }
    throw new IllegalStateException("Unexpected edge type: " + edgeType);
  }

  @Test
  public void equivalent_nodeSetsDiffer() {
    graph.addNode(N1);

    MutableGraph<Integer> g2 = createGraph(edgeType);
    g2.addNode(N2);

    assertThat(graph).isNotEqualTo(g2);
  }

  // Node/edge sets are the same, but node/edge connections differ due to edge type.
  @Test

        .allowsParallelEdges(allowsParallelEdges)
        .nodeOrder(nodeOrder)
        .edgeOrder(edgeOrder)
        .build();
  }

  @Override
  void addNode(Integer n) {
    networkAsMutableNetwork.addNode(n);
  }

  @Override
  void addEdge(Integer n1, Integer n2, String e) {
    networkAsMutableNetwork.addEdge(n1, n2, e);
  }

        .allowsParallelEdges(allowsParallelEdges)
        .nodeOrder(nodeOrder)
        .edgeOrder(edgeOrder)
        .build();
  }

  @Override
  void addNode(Integer n) {
    networkAsMutableNetwork.addNode(n);
  }

  @Override
  void addEdge(Integer n1, Integer n2, String e) {
    networkAsMutableNetwork.addEdge(n1, n2, e);
  }

        .allowsParallelEdges(allowsParallelEdges)
        .nodeOrder(nodeOrder)
        .edgeOrder(edgeOrder)
        .build();
  }

  @Override
  void addNode(Integer n) {
    networkAsMutableNetwork.addNode(n);
  }

  @Override
  void addEdge(Integer n1, Integer n2, String e) {
    networkAsMutableNetwork.addEdge(n1, n2, e);
  }

            .nodeOrder(nodeOrder)
            .edgeOrder(edgeOrder)
            .immutable();

    return networkBuilder.build();
  }

  @Override
  void addNode(Integer n) {
    networkBuilder.addNode(n);
    network = networkBuilder.build();
  }

  @Override
  void addEdge(Integer n1, Integer n2, String e) {
    networkBuilder.addEdge(n1, n2, e);
    network = networkBuilder.build();
  }