*/
  private final Equivalence<? super T> equivalence;

  private final String relationshipName;
  private final String hashName;
  private final ItemReporter itemReporter;
  private final List<ImmutableList<T>> groups = Lists.newArrayList();

  RelationshipTester(
      Equivalence<? super T> equivalence,
      String relationshipName,
      String hashName,

   * Compares two {@code boolean} values, considering {@code true} to be less than {@code false},
   * <i>if</i> the result of this comparison chain has not already been determined.
   *
   * <p>Java 8+ users: you can get the equivalent from {@link Booleans#trueFirst()}. For example:
   *
   * <pre>
   * Comparator.comparing(Foo::isBar, {@link Booleans#trueFirst()})
   * </pre>
   *
   * @since 12.0
   */

 *
 * <p><strong>ReadWriteLocks</strong>
 *
 * <p>While {@code ReadWriteLock} instances have different properties and can form cycles without
 * potential deadlock, this class treats {@code ReadWriteLock} instances as equivalent to
 * traditional exclusive locks. Although this increases the false positives that the locks detect
 * (i.e. cycles that will not actually result in deadlock), it simplifies the algorithm and

   *     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
   *         .collect(toImmutableSetMultimap(str -> str.charAt(0), str -> str.substring(1)));
   *
   * // is equivalent to
   *
   * static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
   *     new ImmutableSetMultimap.Builder<Character, String>()
   *         .put('b', "anana")
   *         .putAll('a', "pple", "sparagus")

  }

  /**
   * Returns an immutable sorted set containing the given elements sorted by their natural ordering.
   * When multiple elements are equivalent according to {@link Comparable#compareTo}, only the first
   * one specified is included.
   *
   * @throws NullPointerException if any element is null
   */

 * {@link #callAndAssertBlocks} method is ever called in a test, the lock-like object must have a
 * method equivalent to {@link java.util.concurrent.locks.ReentrantLock#hasQueuedThread(Thread)}. If
 * the {@link #callAndAssertWaits} method is ever called in a test, the lock-like object must have a
 * method equivalent to {@link
 * java.util.concurrent.locks.ReentrantLock#hasWaiters(java.util.concurrent.locks.Condition)},

  private final Equivalence<T> resultEquivalence;

  FunctionalEquivalence(
      Function<? super F, ? extends @Nullable T> function, Equivalence<T> resultEquivalence) {
    this.function = checkNotNull(function);
    this.resultEquivalence = checkNotNull(resultEquivalence);
  }

  @Override
  protected boolean doEquivalent(F a, F b) {
    return resultEquivalence.equivalent(function.apply(a), function.apply(b));
  }

   * that of {@code ((Character) a).compareTo(b)}.
   *
   * <p><b>Java 7+ users:</b> this method should be treated as deprecated; use the equivalent {@link
   * Character#compare} method instead.
   *
   * @param a the first {@code char} to compare
   * @param b the second {@code char} to compare

@ElementTypesAreNonnullByDefault
final class PairwiseEquivalence<E, T extends @Nullable E> extends Equivalence<Iterable<T>>
    implements Serializable {
  final Equivalence<E> elementEquivalence;

  PairwiseEquivalence(Equivalence<E> elementEquivalence) {
    this.elementEquivalence = Preconditions.checkNotNull(elementEquivalence);
  }

  @Override
  protected boolean doEquivalent(Iterable<T> iterableA, Iterable<T> iterableB) {

     * and Equivalence<Object>.
     */
    private final Equivalence<? super @NonNull T> equivalence;

    @ParametricNullness private final T reference;

    private Wrapper(Equivalence<? super @NonNull T> equivalence, @ParametricNullness T reference) {
      this.equivalence = checkNotNull(equivalence);
      this.reference = reference;
    }