this.incidentEdgeMap = checkNotNull(incidentEdgeMap);
  }

  @Override
  public Set<N> predecessors() {
    return adjacentNodes();
  }

  @Override
  public Set<N> successors() {
    return adjacentNodes();
  }

  @Override
  public Set<E> incidentEdges() {
    return Collections.unmodifiableSet(incidentEdgeMap.keySet());
  }

  @Override

    return delegate().nodeOrder();
  }

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

  @Override
  public Set<N> adjacentNodes(N node) {
    return delegate().adjacentNodes(node);
  }

  @Override
  public Set<N> predecessors(N node) {
    return delegate().predecessors(node);
  }

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

    return delegate().nodeOrder();
  }

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

  @Override
  public Set<N> adjacentNodes(N node) {
    return delegate().adjacentNodes(node);
  }

  @Override
  public Set<N> predecessors(N node) {
    return delegate().predecessors(node);
  }

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

  public int size() {
    if (graph.isDirected()) {
      return graph.inDegree(node)
          + graph.outDegree(node)
          - (graph.successors(node).contains(node) ? 1 : 0);
    } else {
      return graph.adjacentNodes(node).size();
    }
  }

  @Override
  public boolean contains(@Nullable Object obj) {
    if (!(obj instanceof EndpointPair)) {
      return false;
    }

    return delegate().nodeOrder();
  }

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

  @Override
  public Set<N> adjacentNodes(N node) {
    return delegate().adjacentNodes(node);
  }

  @Override
  public Set<N> predecessors(N node) {
    return delegate().predecessors(node);
  }

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

    return delegate().nodeOrder();
  }

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

  @Override
  public Set<N> adjacentNodes(N node) {
    return delegate().adjacentNodes(node);
  }

  @Override
  public Set<N> predecessors(N node) {
    return delegate().predecessors(node);
  }

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

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

      @Override
      public Set<N> adjacentNodes(N node) {
        return AbstractValueGraph.this.adjacentNodes(node);
      }

      @Override
      public Set<N> predecessors(N node) {
        return AbstractValueGraph.this.predecessors(node);
      }

      @Override

            } else {
              return Iterators.unmodifiableIterator(
                  Iterators.transform(
                      graph.adjacentNodes(node).iterator(),
                      (N adjacentNode) -> EndpointPair.unordered(node, adjacentNode)));
            }
          }
        };
    return nodeInvalidatableSet(incident, node);
  }

  @Override
  public int degree(N node) {

      return network.nodeOrder();
    }

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

    @Override
    public Set<N> adjacentNodes(N node) {
      return network.adjacentNodes(node);
    }

    @Override
    public Set<N> predecessors(N node) {
      return network.predecessors(node);
    }

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

 * in a {@link Network}.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 * @param <E> Edge parameter type
 */
interface NetworkConnections<N, E> {

  Set<N> adjacentNodes();

  Set<N> predecessors();

  Set<N> successors();

  Set<E> incidentEdges();

  Set<E> inEdges();

  Set<E> outEdges();

  /**