assertThat(immutableValueGraph.incidentEdgeOrder()).isEqualTo(ElementOrder.stable());
  }

  @Test
  public void incidentEdgeOrder_fromUnorderedGraph_stable() {
    ImmutableValueGraph<String, Integer> immutableValueGraph =
        ImmutableValueGraph.copyOf(
            ValueGraphBuilder.directed()
                .incidentEdgeOrder(ElementOrder.unordered())
                .<String, Integer>build());

    graph = ValueGraphBuilder.directed().incidentEdgeOrder(ElementOrder.unordered()).build();
    assertThat(graph.incidentEdgeOrder()).isEqualTo(ElementOrder.unordered());
  }

  @Test
  public void incidentEdgeOrder_stable() {
    graph = ValueGraphBuilder.directed().incidentEdgeOrder(ElementOrder.stable()).build();
    assertThat(graph.incidentEdgeOrder()).isEqualTo(ElementOrder.stable());
  }

  @Test

    graph = ValueGraphBuilder.directed().incidentEdgeOrder(ElementOrder.unordered()).build();
    assertThat(graph.incidentEdgeOrder()).isEqualTo(ElementOrder.unordered());
  }

  @Test
  public void incidentEdgeOrder_stable() {
    graph = ValueGraphBuilder.directed().incidentEdgeOrder(ElementOrder.stable()).build();
    assertThat(graph.incidentEdgeOrder()).isEqualTo(ElementOrder.stable());
  }

  @Test

            && nodes().contains(endpointPair.nodeU())
            && successors((N) endpointPair.nodeU()).contains(endpointPair.nodeV());
      }
    };
  }

  @Override
  public ElementOrder<N> incidentEdgeOrder() {
    return ElementOrder.unordered();
  }

  @Override
  public Set<EndpointPair<N>> incidentEdges(N node) {
    checkNotNull(node);