*
   * <p>The default value is {@link ElementOrder#insertion() insertion order}.
   */
  public <N1 extends N> NetworkBuilder<N1, E> nodeOrder(ElementOrder<N1> nodeOrder) {
    NetworkBuilder<N1, E> newBuilder = cast();
    newBuilder.nodeOrder = checkNotNull(nodeOrder);
    return newBuilder;
  }

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

    return delegate().isDirected();
  }

  @Override
  public boolean allowsSelfLoops() {
    return delegate().allowsSelfLoops();
  }

  @Override
  public ElementOrder<N> nodeOrder() {
    return delegate().nodeOrder();
  }

  @Override
  public ElementOrder<N> incidentEdgeOrder() {
    return delegate().incidentEdgeOrder();
  }

  @Override
  public Set<N> adjacentNodes(N node) {

    return delegate().isDirected();
  }

  @Override
  public boolean allowsSelfLoops() {
    return delegate().allowsSelfLoops();
  }

  @Override
  public ElementOrder<N> nodeOrder() {
    return delegate().nodeOrder();
  }

  @Override
  public ElementOrder<N> incidentEdgeOrder() {
    return delegate().incidentEdgeOrder();
  }

  @Override
  public Set<N> adjacentNodes(N node) {

    return delegate().isDirected();
  }

  @Override
  public boolean allowsSelfLoops() {
    return delegate().allowsSelfLoops();
  }

  @Override
  public ElementOrder<N> nodeOrder() {
    return delegate().nodeOrder();
  }

  @Override
  public ElementOrder<N> incidentEdgeOrder() {
    return delegate().incidentEdgeOrder();
  }

  @Override
  public Set<N> adjacentNodes(N node) {

    return delegate().allowsParallelEdges();
  }

  @Override
  public boolean allowsSelfLoops() {
    return delegate().allowsSelfLoops();
  }

  @Override
  public ElementOrder<N> nodeOrder() {
    return delegate().nodeOrder();
  }

  @Override
  public ElementOrder<E> edgeOrder() {
    return delegate().edgeOrder();
  }

  @Override
  public Set<N> adjacentNodes(N node) {

      }

      @Override
      public boolean allowsSelfLoops() {
        return AbstractValueGraph.this.allowsSelfLoops();
      }

      @Override
      public ElementOrder<N> nodeOrder() {
        return AbstractValueGraph.this.nodeOrder();
      }

      @Override
      public ElementOrder<N> incidentEdgeOrder() {
        return AbstractValueGraph.this.incidentEdgeOrder();
      }

      @Override

    }

    @Override
    public boolean allowsSelfLoops() {
      return network.allowsSelfLoops();
    }

    @Override
    public ElementOrder<N> nodeOrder() {
      return network.nodeOrder();
    }

    @Override
    public ElementOrder<E> edgeOrder() {
      return network.edgeOrder();
    }

    @Override
    public Set<N> adjacentNodes(N node) {

 *
 * @author James Sexton
 */
abstract class AbstractGraphBuilder<N> {
  final boolean directed;
  boolean allowsSelfLoops = false;
  ElementOrder<N> nodeOrder = ElementOrder.insertion();
  ElementOrder<N> incidentEdgeOrder = ElementOrder.unordered();

  Optional<Integer> expectedNodeCount = Optional.absent();

  /**

    AbstractGraphTest.validateGraph(asGraph);
    assertThat(network.nodes()).isEqualTo(asGraph.nodes());
    assertThat(network.edges().size()).isAtLeast(asGraph.edges().size());
    assertThat(network.nodeOrder()).isEqualTo(asGraph.nodeOrder());
    assertThat(network.isDirected()).isEqualTo(asGraph.isDirected());
    assertThat(network.allowsSelfLoops()).isEqualTo(asGraph.allowsSelfLoops());

    for (E edge : sanityCheckSet(network.edges())) {

public interface Network<N, E> extends SuccessorsFunction<N>, PredecessorsFunction<N> {
  //
  // Network-level accessors
  //

  /** Returns all nodes in this network, in the order specified by {@link #nodeOrder()}. */
  Set<N> nodes();

  /** Returns all edges in this network, in the order specified by {@link #edgeOrder()}. */
  Set<E> edges();

  /**