}

  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));

   */
  @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)}.
   *

    return new Splitter(strategy, omitEmptyStrings, trimmer, maxItems);
  }

  /**
   * Returns a splitter that behaves equivalently to {@code this} splitter, but automatically
   * removes leading and trailing {@linkplain CharMatcher#whitespace whitespace} from each returned
   * substring; equivalent to {@code trimResults(CharMatcher.whitespace())}. For example, {@code

    return new Splitter(strategy, omitEmptyStrings, trimmer, maxItems);
  }

  /**
   * Returns a splitter that behaves equivalently to {@code this} splitter, but automatically
   * removes leading and trailing {@linkplain CharMatcher#whitespace whitespace} from each returned
   * substring; equivalent to {@code trimResults(CharMatcher.whitespace())}. For example, {@code

   * @since 24.0
   */
  @Override
  Set<EndpointPair<N>> incidentEdges(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)}.
   *

   * RoundingMode}. If the {@code RoundingMode} is {@link RoundingMode#DOWN}, then this method is
   * equivalent to regular Java division, {@code p / q}; and if it is {@link RoundingMode#FLOOR},
   * then this method is equivalent to {@link Math#floorDiv(int,int) Math.floorDiv}{@code (p, q)}.
   *
   * @throws ArithmeticException if {@code q == 0}, or if {@code mode == UNNECESSARY} and {@code a}

   * @since 24.0
   */
  @Override
  Set<EndpointPair<N>> incidentEdges(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.

   * 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.
   */