*
     * @return this {@code Builder} object
     * @throws IllegalArgumentException if the introduction of the edge would violate {@link
     *     #allowsSelfLoops()}
     */
    @CanIgnoreReturnValue
    public ImmutableValueGraph.Builder<N, V> putEdgeValue(N nodeU, N nodeV, V value) {
      mutableValueGraph.putEdgeValue(nodeU, nodeV, value);
      return this;
    }

    String graphString = graph.toString();
    assertThat(graphString).contains("isDirected: " + graph.isDirected());
    assertThat(graphString).contains("allowsSelfLoops: " + graph.allowsSelfLoops());

    int nodeStart = graphString.indexOf("nodes:");
    int edgeStart = graphString.indexOf("edges:");
    String nodeString = graphString.substring(nodeStart, edgeStart);

    for (int trial = 0; trial < NUM_TRIALS; ++trial) {
      MutableNetwork<Integer, Object> network =
          networkBuilder.allowsParallelEdges(true).allowsSelfLoops(true).build();

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

      while (network.nodes().size() < NUM_NODES) {

    if (isDirected()) {
      return IntMath.saturatedAdd(predecessors(node).size(), successors(node).size());
    } else {
      Set<N> neighbors = adjacentNodes(node);
      int selfLoopCount = (allowsSelfLoops() && neighbors.contains(node)) ? 1 : 0;
      return IntMath.saturatedAdd(neighbors.size(), selfLoopCount);
    }
  }

  @Override
  public int inDegree(N node) {

   * Attempting to add a self-loop to a network that does not allow them will throw an {@link
   * IllegalArgumentException}.
   */
  boolean allowsSelfLoops();

  /** Returns the order of iteration for the elements of {@link #nodes()}. */
  ElementOrder<N> nodeOrder();

  /** Returns the order of iteration for the elements of {@link #edges()}. */

   * to add a self-loop to a graph that does not allow them will throw an {@link
   * IllegalArgumentException}.
   */
  @Override
  boolean allowsSelfLoops();

  /** Returns the order of iteration for the elements of {@link #nodes()}. */
  @Override
  ElementOrder<N> nodeOrder();

  /**

   * to add a self-loop to a graph that does not allow them will throw an {@link
   * IllegalArgumentException}.
   */
  @Override
  boolean allowsSelfLoops();

  /** Returns the order of iteration for the elements of {@link #nodes()}. */
  @Override
  ElementOrder<N> nodeOrder();

  /**

   * to add a self-loop to a graph that does not allow them will throw an {@link
   * IllegalArgumentException}.
   */
  @Override
  boolean allowsSelfLoops();

  /** Returns the order of iteration for the elements of {@link #nodes()}. */
  @Override
  ElementOrder<N> nodeOrder();

  /**

   * Attempting to add a self-loop to a network that does not allow them will throw an {@link
   * IllegalArgumentException}.
   */
  boolean allowsSelfLoops();

  /** Returns the order of iteration for the elements of {@link #nodes()}. */
  ElementOrder<N> nodeOrder();

  /** Returns the order of iteration for the elements of {@link #edges()}. */