private final EdgeType edgeType;
  private final MutableGraph<Integer> graph;

  // add parameters: directed/undirected
  @Parameters
  public static Collection<Object[]> parameters() {
    return Arrays.asList(new Object[][] {{EdgeType.UNDIRECTED}, {EdgeType.DIRECTED}});
  }

  public GraphEquivalenceTest(EdgeType edgeType) {
    this.edgeType = edgeType;
    this.graph = createGraph(edgeType);
  }

  private final EdgeType edgeType;
  private final MutableGraph<Integer> graph;

  // add parameters: directed/undirected
  @Parameters
  public static Collection<Object[]> parameters() {
    return Arrays.asList(new Object[][] {{EdgeType.UNDIRECTED}, {EdgeType.DIRECTED}});
  }

  public GraphEquivalenceTest(EdgeType edgeType) {
    this.edgeType = edgeType;
    this.graph = createGraph(edgeType);
  }

  //
  // Network properties
  //

  /**
   * Returns true if the edges in this network are directed. Directed edges connect a {@link
   * EndpointPair#source() source node} to a {@link EndpointPair#target() target node}, while
   * undirected edges connect a pair of nodes to each other.
   */
  boolean isDirected();

  /**
   * Returns true if this network allows parallel edges. Attempting to add a parallel edge to a

  //
  // ValueGraph properties
  //

  /**
   * Returns true if the edges in this graph are directed. Directed edges connect a {@link
   * EndpointPair#source() source node} to a {@link EndpointPair#target() target node}, while
   * undirected edges connect a pair of nodes to each other.
   */
  @Override
  boolean isDirected();

  /**

  private static final ImmutableNetwork<String, String> IMMUTABLE_NETWORK_B =
      NetworkBuilder.directed().<String, String>immutable().addNode("B").build();

  public PackageSanityTests() {
    MutableNetwork<String, String> mutableNetworkA = NetworkBuilder.directed().build();
    mutableNetworkA.addNode("a");
    MutableNetwork<String, String> mutableNetworkB = NetworkBuilder.directed().build();

  }

  @Test
  public void incidentEdgeOrder_unordered() {
    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();

  public void transitiveClosure_directedGraph() {
    MutableGraph<Integer> directedGraph = GraphBuilder.directed().allowsSelfLoops(false).build();
    directedGraph.putEdge(N1, N2);
    directedGraph.putEdge(N1, N3);
    directedGraph.putEdge(N2, N3);
    directedGraph.addNode(N4);

    MutableGraph<Integer> expectedClosure = GraphBuilder.directed().allowsSelfLoops(true).build();
    expectedClosure.putEdge(N1, N1);
    expectedClosure.putEdge(N1, N2);

  private static final ImmutableNetwork<String, String> IMMUTABLE_NETWORK_B =
      NetworkBuilder.directed().<String, String>immutable().addNode("B").build();

  public PackageSanityTests() {
    MutableNetwork<String, String> mutableNetworkA = NetworkBuilder.directed().build();
    mutableNetworkA.addNode("a");
    MutableNetwork<String, String> mutableNetworkB = NetworkBuilder.directed().build();

  private final EdgeType edgeType;
  private final MutableNetwork<Integer, String> network;

  // add parameters: directed/undirected
  @Parameters
  public static Collection<Object[]> parameters() {
    return Arrays.asList(new Object[][] {{EdgeType.UNDIRECTED}, {EdgeType.DIRECTED}});
  }

  public NetworkEquivalenceTest(EdgeType edgeType) {
    this.edgeType = edgeType;
    this.network = createNetwork(edgeType);

  private final EdgeType edgeType;
  private final MutableNetwork<Integer, String> network;

  // add parameters: directed/undirected
  @Parameters
  public static Collection<Object[]> parameters() {
    return Arrays.asList(new Object[][] {{EdgeType.UNDIRECTED}, {EdgeType.DIRECTED}});
  }

  public NetworkEquivalenceTest(EdgeType edgeType) {
    this.edgeType = edgeType;
    this.network = createNetwork(edgeType);