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

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

  @Test