links = null;
    return result;
  }

  /*
   * For discussion of the safety of the following methods for operating on predecessors and
   * successors, see the comments near the end of CompactHashMap, noting that the methods here call
   * link(), which is defined at the end of this file.
   */

  private int getPredecessor(int entry) {

   * higher than performing just the operation without enforcing the capacity constraint.
   *
   * This implementation uses a per-segment queue to record a memento of the additions, removals,
   * and accesses that were performed on the map. The queue is drained on writes and when it exceeds
   * its capacity threshold.
   *
   * The Least Recently Used page replacement algorithm was chosen due to its simplicity, high hit

      for (int i = delegateIndex; i < delegates.size(); i++) {
        if (delegates.get(i).setFuture(inputFuture)) {
          recordCompletion();
          // this is technically unnecessary, but should speed up later accesses
          delegateIndex = i + 1;
          return;
        }
      }
      // If all the delegates were complete, no reason for the next listener to have to

      return graph;
    }

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

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

    @Override
    public Set<EndpointPair<N>> incidentEdges(N node) {
      return new IncidentEdgeSet<N>(this, node) {

      }

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

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

      // DO NOT override the AbstractGraph *degree() implementations.
    };
  }

  @Override
  public int degree(N node) {
    if (isDirected()) {

    links = null;
    return result;
  }

  /*
   * For discussion of the safety of the following methods for operating on predecessors and
   * successors, see the comments near the end of CompactHashMap, noting that the methods here call
   * link(), which is defined at the end of this file.
   */

  private int getPredecessor(int entry) {