// Network identity
  //

  /**
   * Returns {@code true} iff {@code object} is a {@link Network} that has the same elements and the
   * same structural relationships as those in this network.
   *
   * <p>Thus, two networks A and B are equal if <b>all</b> of the following are true:
   *
   * <ul>
   *   <li>A and B have equal {@link #isDirected() directedness}.
   *   <li>A and B have equal {@link #nodes() node sets}.

   * {@link #testSeededHashFunctionEquals} because the parameter to {@code goodFastHash} is a size,
   * not a seed, and because that size is rounded up. Thus, {@code goodFastHash} instances with
   * different parameters can be equal. That fact is a problem for {@code
   * testSeededHashFunctionEquals}.
   */
  public void testGoodFastHashEquals() throws Exception {

   * href="https://docs.google.com/spreadsheets/d/1kq4ECwPjHX9B8QUCTPclgsDCXYaj7T-FlT4tB5q3ahk/edit">comparison
   * of several definitions of "whitespace"</a>.)
   *
   * <p>All Unicode White_Space characters are on the BMP and thus supported by this API.
   *
   * <p><b>Note:</b> as the Unicode definition evolves, we will modify this matcher to keep it up to
   * date.
   *
   * @since 19.0 (since 1.0 as constant {@code WHITESPACE})
   */

 * with {@link Collection} itself). Prefer subtypes such as {@link ImmutableSet} or {@link
 * ImmutableList}, which have well-defined {@link #equals} semantics, thus avoiding a common source
 * of bugs and confusion.
 *
 * <h3>About <i>all</i> {@code Immutable-} collections</h3>
 *
 * <p>The remainder of this documentation applies to every public {@code Immutable-} type in this

     * regrettable implementations like our own Sets.filter, Collection.size() is sometimes a
     * linear-time operation, and it can even have side effects. Thus, we limit the special case to
     * List, which is _even more likely_ to have size() implemented to be fast and side-effect-free.
     *

 * with {@link Collection} itself). Prefer subtypes such as {@link ImmutableSet} or {@link
 * ImmutableList}, which have well-defined {@link #equals} semantics, thus avoiding a common source
 * of bugs and confusion.
 *
 * <h3>About <i>all</i> {@code Immutable-} collections</h3>
 *
 * <p>The remainder of this documentation applies to every public {@code Immutable-} type in this

        return unsafeNull(); // See the discussion in getValue().
      }
      /*
       * The cast is safe because updateIndex found the entry for this key. (If it hadn't, then we
       * would have returned above.) Thus, we know that it and its corresponding value are in
       * position `index`.
       */
      V oldValue = uncheckedCastNullableTToT(values[index]);
      if (Objects.equals(oldValue, value)) {
        return value;

  /** Returns the total number of stripes in this instance. */
  public abstract int size();

  /**
   * Returns the stripes that correspond to the passed objects, in ascending (as per {@link
   * #getAt(int)}) order. Thus, threads that use the stripes in the order returned by this method
   * are guaranteed to not deadlock each other.
   *
   * <p>It should be noted that using a {@code Striped<L>} with relatively few stripes, and {@code

  /*
   * @IgnoreJRERequirement should be redundant with the one on Streams itself, but it's necessary as
   * of Animal Sniffer 1.24. Maybe Animal Sniffer processes this nested class before it processes
   * Streams and thus hasn't had a chance to see Streams's annotation?
   */
  @IgnoreJRERequirement
  private abstract static class MapWithIndexSpliterator<
          F extends Spliterator<?>,
          R extends @Nullable Object,

      int expectedSize) {
    return new HashSet<>(Maps.capacity(expectedSize));
  }

  /**
   * Creates a thread-safe set backed by a hash map. The set is backed by a {@link
   * ConcurrentHashMap} instance, and thus carries the same concurrency guarantees.
   *
   * <p>Unlike {@code HashSet}, this class does NOT allow {@code null} to be used as an element. The
   * set is serializable.
   *