AbstractGraphTest.validateGraph(graph);

      for (int i = numNodesToRemove; i < NUM_NODES; ++i) {
        assertThat(graph.removeNode(nodeList.get(i))).isTrue();
      }

      assertThat(graph.nodes()).isEmpty();
      assertThat(graph.edges()).isEmpty(); // no edges can remain if there's no nodes
      AbstractGraphTest.validateGraph(graph);

      Collections.shuffle(nodeList, gen);

      AbstractGraphTest.validateGraph(graph);

      for (int i = numNodesToRemove; i < NUM_NODES; ++i) {
        assertThat(graph.removeNode(nodeList.get(i))).isTrue();
      }

      assertThat(graph.nodes()).isEmpty();
      assertThat(graph.edges()).isEmpty(); // no edges can remain if there's no nodes
      AbstractGraphTest.validateGraph(graph);

      Collections.shuffle(nodeList, gen);

    Graph<Integer> transpose = transpose(directedGraph);
    assertThat(transpose).isEqualTo(expectedTranspose);
    assertThat(transpose(transpose)).isSameInstanceAs(directedGraph);
    AbstractGraphTest.validateGraph(transpose);

    for (Integer node : directedGraph.nodes()) {
      assertThat(directedGraph.inDegree(node)).isSameInstanceAs(transpose.outDegree(node));

    String nodeString = networkString.substring(nodeStart, edgeStart);
    String edgeString = networkString.substring(edgeStart);

    Graph<N> asGraph = network.asGraph();
    AbstractGraphTest.validateGraph(asGraph);
    assertThat(network.nodes()).isEqualTo(asGraph.nodes());
    assertThat(network.edges().size()).isAtLeast(asGraph.edges().size());
    assertThat(network.nodeOrder()).isEqualTo(asGraph.nodeOrder());