return delegate().successors(node);
  }

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

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

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

  @Override
  public EndpointPair<N> incidentNodes(E edge) {

   * EndpointPair<N>} objects (that is, a {@code Network<N, EndpointPair<N>>}). The resulting {@code
   * Network}'s edge-oriented methods (such as {@code inEdges()}) will return views transformed from
   * the corresponding node-oriented methods (such as {@code predecessors()}).
   *
   * <p>This capability facilitates writing implementations of <a

      }

      @Override
      public boolean contains(@Nullable Object obj) {
        return inEdgeMap.containsKey(obj) || outEdgeMap.containsKey(obj);
      }
    };
  }

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

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

  @Override

    }

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

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

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

    @Override
    public EndpointPair<N> incidentNodes(E edge) {

    return nodePairInvalidatableSet(connectionsU.edgesConnecting(nodeV), nodeU, nodeV);
  }

  @Override
  public Set<E> inEdges(N node) {
    return nodeInvalidatableSet(checkedConnections(node).inEdges(), node);
  }

  @Override
  public Set<E> outEdges(N node) {
    return nodeInvalidatableSet(checkedConnections(node).outEdges(), node);
  }

  @Override

 * @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();

  /**
   * Returns the set of edges connecting the origin node to {@code node}. For networks without
   * parallel edges, this set cannot be of size greater than one.
   */

    return adjacentNodes();
  }

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

  @Override
  public Set<E> inEdges() {
    return incidentEdges();
  }

  @Override
  public Set<E> outEdges() {
    return incidentEdges();
  }

  @Override
  public N adjacentNode(E edge) {

  //

  /**
   * Returns a live view of the edges whose {@link #incidentNodes(Object) incident nodes} in this
   * network include {@code node}.
   *
   * <p>This is equal to the union of {@link #inEdges(Object)} and {@link #outEdges(Object)}.
   *
   * <p>If {@code node} is removed from the network after this method is called, the {@code Set}
   * {@code view} returned by this method will be invalidated, and will throw {@code

      }

      @Override
      public Set<EndpointPair<N>> incidentEdges(N node) {
        return AbstractBaseGraph.this.incidentEdges(node);
      }

      @Override
      public Set<EndpointPair<N>> inEdges(N node) {
        checkNotNull(node);
        checkArgument(nodes().contains(node));
        IncidentEdgeSet<N> incident =
            new IncidentEdgeSet<N>(this, node, IncidentEdgeSet.EdgeType.INCOMING) {

  }

  private static <N, E> NetworkConnections<N, E> connectionsOf(Network<N, E> network, N node) {
    if (network.isDirected()) {
      Map<E, N> inEdgeMap = Maps.asMap(network.inEdges(node), sourceNodeFn(network));
      Map<E, N> outEdgeMap = Maps.asMap(network.outEdges(node), targetNodeFn(network));
      int selfLoopCount = network.edgesConnecting(node, node).size();