}

  public void testEquivalentTo() {
    Predicate<@Nullable Object> equalTo1 = Equivalence.equals().equivalentTo("1");
    assertTrue(equalTo1.apply("1"));
    assertFalse(equalTo1.apply("2"));
    assertFalse(equalTo1.apply(null));
    Predicate<@Nullable Object> isNull = Equivalence.equals().equivalentTo(null);
    assertFalse(isNull.apply("1"));
    assertFalse(isNull.apply("2"));
    assertTrue(isNull.apply(null));

   *   <li>If {@code equivalent(x, y)} and {@code equivalent(y, z)} are both true, then {@code
   *       equivalent(x, z)} is also true (<i>transitive</i> property)
   * </ul>
   *
   * <p>Note that all calls to {@code equivalent(x, y)} are expected to return the same result as
   * long as neither {@code x} nor {@code y} is modified.
   */
  public final boolean equivalent(@Nullable T a, @Nullable T b) {
    if (a == b) {

          || (a = as[(n - 1) & hc[0]]) == null
          || !(uncontended = a.cas(v = a.value, v + x))) retryUpdate(x, hc, uncontended);
    }
  }

  /** Equivalent to {@code add(1)}. */
  @Override
  public void increment() {
    add(1L);
  }

  /** Equivalent to {@code add(-1)}. */
  public void decrement() {
    add(-1L);
  }

  /**

   */
  @Override
  Set<N> successors(N node);

  /**
   * Returns the count of {@code node}'s incident edges, counting self-loops twice (equivalently,
   * the number of times an edge touches {@code node}).
   *
   * <p>For directed graphs, this is equal to {@code inDegree(node) + outDegree(node)}.
   *

   * stream is empty.
   *
   * <p>Equivalent to {@code stream.reduce((a, b) -> b)}, but may perform significantly better. This
   * method's runtime will be between O(log n) and O(n), performing better on <a
   * href="http://gee.cs.oswego.edu/dl/html/StreamParallelGuidance.html">efficiently splittable</a>
   * streams.
   *
   * <p>If the stream has nondeterministic order, this has equivalent semantics to {@link

   * @since 32.0.0
   */
  public static void rotate(int[] array, int distance, int fromIndex, int toIndex) {
    // There are several well-known algorithms for rotating part of an array (or, equivalently,
    // exchanging two blocks of memory). This classic text by Gries and Mills mentions several:
    // https://ecommons.cornell.edu/bitstream/handle/1813/6292/81-452.pdf.
    // (1) "Reversal", the one we have here.

    }
    return changed;
  }

  /**
   * For each occurrence of an element {@code e} in {@code occurrencesToRemove}, removes one
   * occurrence of {@code e} in {@code multisetToModify}.
   *
   * <p>Equivalently, this method modifies {@code multisetToModify} so that {@code
   * multisetToModify.count(e)} is set to {@code Math.max(0, multisetToModify.count(e) -
   * Iterables.frequency(occurrencesToRemove, e))}.
   *

    }
    return changed;
  }

  /**
   * For each occurrence of an element {@code e} in {@code occurrencesToRemove}, removes one
   * occurrence of {@code e} in {@code multisetToModify}.
   *
   * <p>Equivalently, this method modifies {@code multisetToModify} so that {@code
   * multisetToModify.count(e)} is set to {@code Math.max(0, multisetToModify.count(e) -
   * Iterables.frequency(occurrencesToRemove, e))}.
   *

   * implicit).
   */
  protected Ordering() {}

  // Instance-based factories (and any static equivalents)

  /**
   * Returns the reverse of this ordering; the {@code Ordering} equivalent to {@link
   * Collections#reverseOrder(Comparator)}.
   *
   * <p><b>Java 8+ users:</b> Use {@code thisComparator.reversed()} instead.
   */

   */
  Set<E> outEdges(N node);

  /**
   * Returns the count of {@code node}'s {@link #incidentEdges(Object) incident edges}, counting
   * self-loops twice (equivalently, the number of times an edge touches {@code node}).
   *
   * <p>For directed networks, this is equal to {@code inDegree(node) + outDegree(node)}.
   *