return Collections.unmodifiableSet(adjacentNodeValues.keySet());
  }

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

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

  @Override
  public Iterator<EndpointPair<N>> incidentEdgeIterator(N thisNode) {
    return Iterators.transform(
        adjacentNodeValues.keySet().iterator(),

        return sb.toString();
    }

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

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public String getAuthRealm() {
        checkSpecifiedProperty("authRealm");
        return convertEmptyToNull(authRealm);

 *
 * {@snippet :
 * someGraphAlgorithm(startNode, node -> ImmutableList.of(node.mother(), node.father()));
 * }
 *
 * <p>Graph algorithms that need additional capabilities (accessing both predecessors and
 * successors, iterating over the edges, etc.) should declare their input to be of a type that
 * provides those capabilities, such as {@link Graph}, {@link ValueGraph}, or {@link Network}.
 *
 * <h3>Additional documentation</h3>
 *

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public Boolean getAvailable() {
        checkSpecifiedProperty("available");
        return available;
    }

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public Boolean getAvailable() {
        checkSpecifiedProperty("available");
        return available;
    }

    /**
     * Lock object for synchronizing access to active thread count.
     */
    protected Object activeThreadCountLock = new Object();

    /**
     * Atomic counter for tracking the number of accesses made.
     */
    protected AtomicLong accessCount = new AtomicLong(0);

    /**
     * Current status of the crawler.
     */
    protected volatile CrawlerStatus status = CrawlerStatus.INITIALIZING;

        return sb.toString();
    }

    // ===================================================================================
    //                                                                            Accessor
    //                                                                            ========
    public Boolean getAvailable() {
        checkSpecifiedProperty("available");
        return available;
    }

   * Creates an {@code MonitorBasedArrayBlockingQueue} with the given (fixed) capacity and the
   * specified access policy.
   *
   * @param capacity the capacity of this queue
   * @param fair if {@code true} then queue accesses for threads blocked on insertion or removal,
   *     are processed in FIFO order; if {@code false} the access order is unspecified.
   * @throws IllegalArgumentException if {@code capacity} is less than 1
   */

    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) {