@Override
  public Graph<N> asGraph() {
    return new AbstractGraph<N>() {
      @Override
      public Set<N> nodes() {
        return AbstractNetwork.this.nodes();
      }

      @Override
      public Set<EndpointPair<N>> edges() {
        if (allowsParallelEdges()) {
          return super.edges(); // Defer to AbstractGraph implementation.
        }

   * <p>A reference implementation of this is provided by {@link AbstractGraph#equals(Object)}.
   */
  @Override
  boolean equals(@Nullable Object object);

  /**
   * Returns the hash code for this graph. The hash code of a graph is defined as the hash code of
   * the set returned by {@link #edges()}.
   *
   * <p>A reference implementation of this is provided by {@link AbstractGraph#hashCode()}.
   */
  @Override
  int hashCode();

      return EndpointPair.ordered(endpoints.target(), endpoints.source());
    }
    return endpoints;
  }

  // NOTE: this should work as long as the delegate graph's implementation of edges() (like that of
  // AbstractGraph) derives its behavior from calling successors().
  private static final class TransposedGraph<N> extends ForwardingGraph<N> {
    private final Graph<N> graph;

    TransposedGraph(Graph<N> graph) {