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

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

  @Test

  }

  @Test
  public void hasEdgeConnecting_correct() {
    putEdge(N1, N2);
    assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(N1, N2))).isTrue();
  }

  @Test
  public void hasEdgeConnecting_backwards() {
    putEdge(N1, N2);
    assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(N2, N1))).isFalse();
  }

  @Test
  public void hasEdgeConnecting_mismatch() {
    putEdge(N1, N2);

  }

  @Test
  public void hasEdgeConnecting_correct() {
    putEdge(N1, N2);
    assertThat(graph.hasEdgeConnecting(EndpointPair.unordered(N1, N2))).isTrue();
    assertThat(graph.hasEdgeConnecting(EndpointPair.unordered(N2, N1))).isTrue();
  }

  @Test
  public void hasEdgeConnecting_mismatch() {
    putEdge(N1, N2);
    assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(N1, N2))).isFalse();

  }

  @Test
  public void hasEdgeConnecting_correct() {
    putEdge(N1, N2);
    assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(N1, N2))).isTrue();
  }

  @Test
  public void hasEdgeConnecting_backwards() {
    putEdge(N1, N2);
    assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(N2, N1))).isFalse();
  }

  @Test
  public void hasEdgeConnecting_mismatch() {
    putEdge(N1, N2);

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

      for (EndpointPair<N> endpoints : sanityCheckSet(graph.incidentEdges(node))) {
        if (graph.isDirected()) {
          assertThat(graph.hasEdgeConnecting(endpoints.source(), endpoints.target())).isTrue();
        } else {

  }

  @Test
  public void hasEdgeConnecting_correct() {
    putEdge(N1, N2);
    assertThat(graph.hasEdgeConnecting(EndpointPair.unordered(N1, N2))).isTrue();
    assertThat(graph.hasEdgeConnecting(EndpointPair.unordered(N2, N1))).isTrue();
  }

  @Test
  public void hasEdgeConnecting_mismatch() {
    putEdge(N1, N2);
    assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(N1, N2))).isFalse();

   * equivalent to {@code nodes().contains(nodeU) && successors(nodeU).contains(nodeV)}.
   *
   * <p>In an undirected graph, this is equal to {@code hasEdgeConnecting(nodeV, nodeU)}.
   *
   * @since 23.0
   */
  @Override
  boolean hasEdgeConnecting(N nodeU, N nodeV);

  /**
   * Returns true if there is an edge that directly connects {@code endpoints} (in the order, if

  }

  @Test
  public void hasEdgeConnecting_disconnectedNodes() {
    addNode(N1);
    addNode(N2);
    assertThat(network.hasEdgeConnecting(N1, N2)).isFalse();
  }

  @Test
  public void hasEdgesConnecting_nodesNotInGraph() {
    addNode(N1);
    addNode(N2);
    assertThat(network.hasEdgeConnecting(N1, NODE_NOT_IN_GRAPH)).isFalse();

  }

  @Test
  public void hasEdgeConnecting_disconnectedNodes() {
    addNode(N1);
    addNode(N2);
    assertThat(network.hasEdgeConnecting(N1, N2)).isFalse();
  }

  @Test
  public void hasEdgesConnecting_nodesNotInGraph() {
    addNode(N1);
    addNode(N2);
    assertThat(network.hasEdgeConnecting(N1, NODE_NOT_IN_GRAPH)).isFalse();

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

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

  @Test