*       #element}, and {@link #size} are constant-time.
 *   <li>The enqueuing and dequeuing operations ({@link #offer}, {@link #add}, and all the forms of
 *       {@link #poll} and {@link #remove()}) run in {@code O(log n) time}.
 *   <li>The {@link #remove(Object)} and {@link #contains} operations require linear ({@code O(n)})
 *       time.
 *   <li>If you only access one end of the queue, and don't use a maximum size, this class is

 * information on "bogons", including lists of IPv6 bogon space, see:
 *
 * <ul>
 *   <li><a target="_parent"
 *       href="http://en.wikipedia.org/wiki/Bogon_filtering">http://en.wikipedia.
 *       org/wiki/Bogon_filtering</a>
 *   <li><a target="_parent"
 *       href="http://www.cymru.com/Bogons/ipv6.txt">http://www.cymru.com/Bogons/ ipv6.txt</a>
 *   <li><a target="_parent" href="http://www.cymru.com/Bogons/v6bogon.html">http://www.cymru.com/

 * class. For example, testing that {@code nodes()} method returns the set of the nodes in the
 * graph. The following test cases are left for the subclasses to handle:
 *
 * <ul>
 *   <li>Test cases related to whether the graph is directed or undirected.
 *   <li>Test cases related to the specific implementation of the {@link Graph} interface.
 * </ul>
 *
 * TODO(user): Make this class generic (using <N, E>) for all node and edge types.

 * terms</a>):
 *
 * <ul>
 *   <li>directed graphs
 *   <li>undirected graphs
 *   <li>graphs that do/don't allow parallel edges
 *   <li>graphs that do/don't allow self-loops
 *   <li>graphs whose nodes/edges are insertion-ordered, sorted, or unordered
 *   <li>graphs whose edges are unique objects
 * </ul>
 *
 * <h3>Building a {@code Network}</h3>
 *

  }

  /**
   * Returns a fresh instance for {@code type} if possible. The returned instance could be:
   *
   * <ul>
   *   <li>exactly of the given type, including generic type parameters, such as {@code
   *       ImmutableList<String>};
   *   <li>of the raw type;
   *   <li>null if no value can be generated.
   * </ul>
   */
  final @Nullable Object generateFresh(TypeToken<?> type) {

 * href="https://github.com/google/guava/wiki/GraphsExplained#definitions">definitions of
 * terms</a>):
 *
 * <ul>
 *   <li>directed graphs
 *   <li>undirected graphs
 *   <li>graphs that do/don't allow self-loops
 *   <li>graphs whose nodes/edges are insertion-ordered, sorted, or unordered
 * </ul>
 *
 * <p>{@code Graph} explicitly does not support parallel edges, and forbids implementations or

   * WritableByteChannel)}:
   *
   * <ol>
   *   <li>Use sendfile(2) or equivalent. Requires that both the input channel and the output
   *       channel have their own file descriptors. Generally this only happens when both channels
   *       are files or sockets. This performs zero copies - the bytes never enter userspace.
   *   <li>Use mmap(2) or equivalent. Requires that either the input channel or the output channel

   * the given {@code comparator}.
   *
   * <p>In detail, this method asserts
   *
   * <ul>
   *   <li><i>reflexivity</i>: {@code comparator.compare(t, t) = 0} for all {@code t} in {@code
   *       valuesInExpectedOrder}; and
   *   <li><i>consistency</i>: {@code comparator.compare(ti, tj) < 0} and {@code
   *       comparator.compare(tj, ti) > 0} for {@code i < j}, where {@code ti =

   * IllegalStateException} if it is accessed in any way, with the following exceptions:
   *
   * <ul>
   *   <li>{@code view.equals(view)} evaluates to {@code true} (but any other `equals()` expression
   *       involving {@code view} will throw)
   *   <li>{@code hashCode()} does not throw
   *   <li>if {@code node} is re-added to the graph after having been removed, {@code view}'s
   *       behavior is undefined
   * </ul>
   *

    return new IteratorOperation() {
      @Override
      public @Nullable Object execute(Iterator<?> iterator) {
        @SuppressWarnings("unchecked")
        ListIterator<E> li = (ListIterator<E>) iterator;
        li.set(toInsert);
        return null;
      }
    };
  }

  abstract static class Stimulus<E extends @Nullable Object, T extends Iterator<E>> {
    private final String toString;