}
    throw new IllegalStateException("Unexpected edge type: " + edgeType);
  }

  @Test
  public void equivalent_nodeSetsDiffer() {
    graph.addNode(N1);

    MutableGraph<Integer> g2 = createGraph(edgeType);
    g2.addNode(N2);

    assertThat(graph).isNotEqualTo(g2);
  }

  // Node/edge sets are the same, but node/edge connections differ due to edge type.
  @Test

    }
    throw new IllegalStateException("Unexpected edge type: " + edgeType);
  }

  @Test
  public void equivalent_nodeSetsDiffer() {
    graph.addNode(N1);

    MutableGraph<Integer> g2 = createGraph(edgeType);
    g2.addNode(N2);

    assertThat(graph).isNotEqualTo(g2);
  }

  // Node/edge sets are the same, but node/edge connections differ due to edge type.
  @Test

    assertThat(hasCycle(undirectedGraph)).isFalse();
  }

  @Test
  public void hasCycle_isolatedNodes() {
    for (MutableGraph<Integer> graph : graphsToTest) {
      graph.addNode(1);
      graph.addNode(2);
    }
    assertThat(hasCycle(directedGraph)).isFalse();
    assertThat(hasCycle(undirectedGraph)).isFalse();
  }

  @Test
  public void hasCycle_oneEdge() {

   * <p><b>Nodes must be unique</b>, just as {@code Map} keys must be. They must also be non-null.
   *
   * @return {@code true} if the network was modified as a result of this call
   */
  @CanIgnoreReturnValue
  boolean addNode(N node);

  /**
   * Adds {@code edge} connecting {@code nodeU} to {@code nodeV}.
   *
   * <p>If the graph is directed, {@code edge} will be directed in this graph; otherwise, it will be
   * undirected.
   *

        return this;
    }

    public PopularWordsRequestBuilder addTag(final String tag) {
        request.addTag(tag);
        return this;
    }

    public PopularWordsRequestBuilder addRole(final String role) {
        request.addRole(role);
        return this;
    }

    public PopularWordsRequestBuilder addField(final String field) {
        request.addField(field);
        return this;
    }

        return this;
    }

    public SuggestRequestBuilder addTag(final String tag) {
        request.addTag(tag);
        return this;
    }

    public SuggestRequestBuilder addRole(final String role) {
        request.addRole(role);
        return this;
    }

    public SuggestRequestBuilder addField(final String field) {
        request.addField(field);
        return this;
    }

      assertThat(network.nodes()).isEmpty();
      assertThat(network.edges()).isEmpty();
      AbstractNetworkTest.validateNetwork(network);

      while (network.nodes().size() < NUM_NODES) {
        network.addNode(gen.nextInt(NODE_POOL_SIZE));
      }
      ArrayList<Integer> nodeList = new ArrayList<>(network.nodes());
      for (int i = 0; i < NUM_EDGES; ++i) {
        // Parallel edges are allowed, so this should always succeed.

    }
    throw new IllegalStateException("Unexpected edge type: " + edgeType);
  }

  @Test
  public void equivalent_nodeSetsDiffer() {
    network.addNode(N1);

    MutableNetwork<Integer, String> g2 = createNetwork(edgeType);
    g2.addNode(N2);

    assertThat(network).isNotEqualTo(g2);
  }

  // Node sets are the same, but edge sets differ.
  @Test
  public void equivalent_edgeSetsDiffer() {

    }
    throw new IllegalStateException("Unexpected edge type: " + edgeType);
  }

  @Test
  public void equivalent_nodeSetsDiffer() {
    network.addNode(N1);

    MutableNetwork<Integer, String> g2 = createNetwork(edgeType);
    g2.addNode(N2);

    assertThat(network).isNotEqualTo(g2);
  }

  // Node sets are the same, but edge sets differ.
  @Test
  public void equivalent_edgeSetsDiffer() {

    }

    public void setWindowSize(final int windowSize) {
        this.windowSize = windowSize;
    }

    public void addTag(final String tag) {
        tags.add(tag);
    }

    public void addRole(final String role) {
        roles.add(role);
    }

    public void addField(final String field) {
        fields.add(field);
    }

    public void addLanguage(final String lang) {