*
 * @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();

  /**
   * Returns the set of edges connecting the origin node to {@code node}. For networks without

    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
  public Set<E> inEdges() {

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getCreatedBy() {
        checkSpecifiedProperty("createdBy");
        return convertEmptyToNull(createdBy);

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getCreatedBy() {
        checkSpecifiedProperty("createdBy");
        return convertEmptyToNull(createdBy);

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getCreatedBy() {
        checkSpecifiedProperty("createdBy");
        return convertEmptyToNull(createdBy);

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getCreatedBy() {
        checkSpecifiedProperty("createdBy");
        return convertEmptyToNull(createdBy);

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getBoostExpr() {
        checkSpecifiedProperty("boostExpr");
        return convertEmptyToNull(boostExpr);

     * starting at the root object contained in this value source, apply each part
     * to the object graph below this root, using either 'getXXX()' or 'isXXX()'
     * accessor types to resolve the value for each successive expression part.
     * Finally, return the result of the last expression part's resolution.</p>
     *
     * <p><b>NOTE:</b> The object-graph navigation actually takes place via the

    checkState(selfLoopCount <= inEdgeMap.size() && selfLoopCount <= outEdgeMap.size());
  }

  @Override
  public Set<N> adjacentNodes() {
    return Sets.union(predecessors(), successors());
  }

  @Override
  public Set<E> incidentEdges() {
    return new AbstractSet<E>() {
      @Override
      public UnmodifiableIterator<E> iterator() {
        Iterable<E> incidentEdges =

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getContent() {
        checkSpecifiedProperty("content");
        return convertEmptyToNull(content);
    }