* @since 20.0
 */
@Beta
public abstract class AbstractNetwork<N, E> implements Network<N, E> {
  /** Constructor for use by subclasses. */
  public AbstractNetwork() {}

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

      @Override

 * @since 20.0
 */
@Beta
public abstract class AbstractNetwork<N, E> implements Network<N, E> {
  /** Constructor for use by subclasses. */
  public AbstractNetwork() {}

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

      @Override

    N nodeV = endpoints.nodeV();
    return nodes().contains(nodeU) && successors(nodeU).contains(nodeV);
  }

  @Override
  public Network<N, EndpointPair<N>> asNetwork() {
    return new AbstractNetwork<N, EndpointPair<N>>() {
      @Override
      public Set<N> nodes() {
        return AbstractBaseGraph.this.nodes();
      }

      @Override
      public Set<EndpointPair<N>> edges() {

   * the order in which they are iterated over, are irrelevant.
   *
   * <p>A reference implementation of this is provided by {@link AbstractNetwork#equals(Object)}.
   */
  @Override
  boolean equals(@Nullable Object object);

  /**
   * Returns the hash code for this network. The hash code of a network is defined as the hash code