while (graph.edges().size() < NUM_EDGES) {
        graph.putEdge(getRandomElement(nodeList, gen), getRandomElement(nodeList, gen));
      }
      ArrayList<EndpointPair<Integer>> edgeList = new ArrayList<>(graph.edges());

      assertThat(graph.nodes()).hasSize(NUM_NODES);
      assertThat(graph.edges()).hasSize(NUM_EDGES);
      AbstractGraphTest.validateGraph(graph);

            .putEdgeValue(2, 3, "2-3")
            .putEdgeValue(1, 2, "1-2")
            .build();

    assertThat(graph.incidentEdges(2))
        .containsExactly(
            EndpointPair.ordered(2, 1), EndpointPair.ordered(2, 3), EndpointPair.ordered(1, 2))
        .inOrder();
  }

  @Test
  public void immutableValueGraphBuilder_incidentEdgeOrder_stable() {
    ImmutableValueGraph<Integer, String> graph =

    checkNotNull(nodeU, "nodeU");
    checkNotNull(nodeV, "nodeV");
    checkNotNull(edge, "edge");

    if (containsEdge(edge)) {
      EndpointPair<N> existingIncidentNodes = incidentNodes(edge);
      EndpointPair<N> newIncidentNodes = EndpointPair.of(this, nodeU, nodeV);
      checkArgument(
          existingIncidentNodes.equals(newIncidentNodes),
          REUSING_EDGE,
          edge,

    assertThat(network.incidentNodes(10)).isEqualTo(EndpointPair.ordered("A", "B"));
  }

  @Test
  public void immutableNetworkBuilder_putEdgeFromEndpointPair() {
    ImmutableNetwork<String, Integer> network =
        NetworkBuilder.directed()
            .<String, Integer>immutable()
            .addEdge(EndpointPair.ordered("A", "B"), 10)
            .build();

    assertThat(graph.nodes()).containsExactly("A", "B");
    assertThat(graph.edges()).containsExactly(EndpointPair.ordered("A", "B"));
  }

  @Test
  public void immutableGraphBuilder_putEdgeFromEndpointPair() {
    ImmutableGraph<String> graph =
        GraphBuilder.directed().<String>immutable().putEdge(EndpointPair.ordered("A", "B")).build();

    assertThat(graph.nodes()).containsExactly("A", "B");

    setDistinctValues(NetworkBuilder.class, NETWORK_BUILDER_A, NETWORK_BUILDER_B);
    setDistinctValues(Network.class, IMMUTABLE_NETWORK_A, IMMUTABLE_NETWORK_B);
    setDefault(EndpointPair.class, EndpointPair.ordered("A", "B"));
  }

  @Override
  public void testNulls() throws Exception {
    try {
      super.testNulls();
    } catch (AssertionFailedError e) {

  }

  @Override
  public Set<N> successors() {
    return adjacentNodes();
  }

  @Override
  public Iterator<EndpointPair<N>> incidentEdgeIterator(N thisNode) {
    return Iterators.transform(
        adjacentNodeValues.keySet().iterator(),
        (N incidentNode) -> EndpointPair.unordered(thisNode, incidentNode));
  }

  @Override
  @CheckForNull
  public V value(N node) {

    assertThat(graph.nodes()).containsExactly("A", "B");
    assertThat(graph.edges()).containsExactly(EndpointPair.ordered("A", "B"));
  }

  @Test
  public void immutableGraphBuilder_putEdgeFromEndpointPair() {
    ImmutableGraph<String> graph =
        GraphBuilder.directed().<String>immutable().putEdge(EndpointPair.ordered("A", "B")).build();

    assertThat(graph.nodes()).containsExactly("A", "B");

    return delegate().predecessors(node);
  }

  @Override
  public Set<N> successors(N node) {
    return delegate().successors(node);
  }

  @Override
  public Set<EndpointPair<N>> incidentEdges(N node) {
    return delegate().incidentEdges(node);
  }

  @Override
  public int degree(N node) {
    return delegate().degree(node);
  }

  @Override
  public int inDegree(N node) {

  }

  @Override
  public Set<EndpointPair<N>> incidentEdges(N node) {
    GraphConnections<N, V> connections = checkedConnections(node);
    IncidentEdgeSet<N> incident =
        new IncidentEdgeSet<N>(this, node) {
          @Override
          public Iterator<EndpointPair<N>> iterator() {
            return connections.incidentEdgeIterator(node);
          }
        };