// Node/edge sets and node/edge connections are the same, but graph properties differ.
  // In this case the graphs are considered equivalent; the property differences are irrelevant.
  @Test
  public void equivalent_propertiesDiffer() {
    graph.putEdge(N1, N2);

    MutableGraph<Integer> g2 =
        GraphBuilder.from(graph).allowsSelfLoops(!graph.allowsSelfLoops()).build();
    g2.putEdge(N1, N2);

  // Node/edge sets and node/edge connections are the same, but network properties differ.
  // (In this case the networks are considered equivalent; the property differences are irrelevant.)
  @Test
  public void equivalent_propertiesDiffer() {
    network.addEdge(N1, N2, E12);

    MutableNetwork<Integer, String> g2 =
        NetworkBuilder.from(network)
            .allowsParallelEdges(!network.allowsParallelEdges())

  // Node/edge sets and node/edge connections are the same, but network properties differ.
  // (In this case the networks are considered equivalent; the property differences are irrelevant.)
  @Test
  public void equivalent_propertiesDiffer() {
    network.addEdge(N1, N2, E12);

    MutableNetwork<Integer, String> g2 =
        NetworkBuilder.from(network)
            .allowsParallelEdges(!network.allowsParallelEdges())