}

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

    populateStarShapedGraph();

    assertThat(graph.edges())
        .containsExactly(
            EndpointPair.ordered(2, 1),
            EndpointPair.ordered(1, 4),
            EndpointPair.ordered(1, 3),
            EndpointPair.ordered(1, 2),
            EndpointPair.ordered(3, 1),
            EndpointPair.ordered(5, 1))
        .inOrder();
  }

  @Test

      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);

  Graph<N> asGraph();

  //
  // ValueGraph properties
  //

  /**
   * Returns true if the edges in this graph are directed. Directed edges connect a {@link
   * EndpointPair#source() source node} to a {@link EndpointPair#target() target node}, while
   * undirected edges connect a pair of nodes to each other.
   */
  @Override
  boolean isDirected();

  /**

  }

  @Override
  public boolean putEdge(N nodeU, N nodeV) {
    return backingValueGraph.putEdgeValue(nodeU, nodeV, Presence.EDGE_EXISTS) == null;
  }

  @Override
  public boolean putEdge(EndpointPair<N> endpoints) {
    validateEndpoints(endpoints);
    return putEdge(endpoints.nodeU(), endpoints.nodeV());
  }

  @Override
  public boolean removeNode(N node) {
    return backingValueGraph.removeNode(node);

    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,

    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) {

   * any, specified by {@code endpoints}).
   *
   * <p>Unlike the other {@code EndpointPair}-accepting methods, this method does not throw if the
   * endpoints are unordered and the network is directed; it simply returns {@code false}. This is
   * for consistency with {@link Graph#hasEdgeConnecting(EndpointPair)} and {@link
   * ValueGraph#hasEdgeConnecting(EndpointPair)}.
   *
   * @since 27.1
   */
  @Override

    assertThat(graph.hasEdgeConnecting(EndpointPair.unordered(1, 2))).isFalse();
    assertThat(graph.hasEdgeConnecting(EndpointPair.unordered(2, 1))).isFalse();
  }

  @Test
  public void hasEdgeConnecting_undirected_correct() {
    graph = ValueGraphBuilder.undirected().build();
    graph.putEdgeValue(1, 2, "A");
    assertThat(graph.hasEdgeConnecting(EndpointPair.unordered(1, 2))).isTrue();
  }

  @Test

        assertThat(graph.hasEdgeConnecting(predecessor, node)).isTrue();
        assertThat(graph.incidentEdges(node)).contains(EndpointPair.of(graph, predecessor, node));
      }

      for (N successor : sanityCheckSet(graph.successors(node))) {
        allEndpointPairs.add(EndpointPair.of(graph, node, successor));
        assertThat(graph.predecessors(successor)).contains(node);