/** Test an empty collection. */
  ZERO(0),
  /** Test a one-element collection. */
  ONE(1),
  /** Test a three-element collection. */
  SEVERAL(3),
  /*
   * TODO: add VERY_LARGE, noting that we currently assume that the fourth
   * sample element is not in any collection
   */

  ANY(ZERO, ONE, SEVERAL);

  private final Set<Feature<? super Collection>> implied;
  private final @Nullable Integer numElements;

  /** Test an empty collection. */
  ZERO(0),
  /** Test a one-element collection. */
  ONE(1),
  /** Test a three-element collection. */
  SEVERAL(3),
  /*
   * TODO: add VERY_LARGE, noting that we currently assume that the fourth
   * sample element is not in any collection
   */

  ANY(ZERO, ONE, SEVERAL);

  private final Set<Feature<? super Collection>> implied;
  private final @Nullable Integer numElements;

    expectContents(Arrays.asList(elements));
  }

  /**
   * Asserts that the collection under test contains exactly the given elements, respecting
   * cardinality but not order. Subclasses may override this method to provide stronger assertions,
   * e.g., to check ordering in lists, but realize that <strong>unless a test extends {@link

    if (obj == this) {
      return true;
    }
    if (obj instanceof FunctionalEquivalence) {
      FunctionalEquivalence<?, ?> that = (FunctionalEquivalence<?, ?>) obj;
      return function.equals(that.function) && resultEquivalence.equals(that.resultEquivalence);
    }
    return false;
  }

  @Override
  public int hashCode() {
    return Objects.hashCode(function, resultEquivalence);
  }

    }
    if (!(object instanceof Set)) {
      return false;
    }

    Set<?> that = (Set<?>) object;
    if (size() != that.size()) {
      return false;
    } else if (isEmpty()) {
      return true;
    }

    if (SortedIterables.hasSameComparator(comparator, that)) {
      Iterator<?> otherIterator = that.iterator();
      try {
        Iterator<E> iterator = iterator();

 *
 * log.info("time: " + stopwatch); // formatted string like "12.3 ms"
 * }</pre>
 *
 * <p>The state-changing methods are not idempotent; it is an error to start or stop a stopwatch
 * that is already in the desired state.
 *
 * <p>When testing code that uses this class, use {@link #createUnstarted(Ticker)} or {@link
 * #createStarted(Ticker)} to supply a fake or mock ticker. This allows you to simulate any valid
 * behavior of the stopwatch.
 *

  public boolean equals(@CheckForNull Object object) {
    if (object == this) {
      return true;
    }
    if (object instanceof NullsFirstOrdering) {
      NullsFirstOrdering<?> that = (NullsFirstOrdering<?>) object;
      return this.ordering.equals(that.ordering);
    }
    return false;
  }

  @Override
  public int hashCode() {
    return ordering.hashCode() ^ 957692532; // meaningless
  }

  @Override

  public boolean equals(@CheckForNull Object object) {
    if (object == this) {
      return true;
    }
    if (object instanceof NullsLastOrdering) {
      NullsLastOrdering<?> that = (NullsLastOrdering<?>) object;
      return this.ordering.equals(that.ordering);
    }
    return false;
  }

  @Override
  public int hashCode() {
    return ordering.hashCode() ^ -921210296; // meaningless
  }

  @Override

  public boolean equals(@CheckForNull Object object) {
    if (object == this) {
      return true;
    }
    if (object instanceof NullsLastOrdering) {
      NullsLastOrdering<?> that = (NullsLastOrdering<?>) object;
      return this.ordering.equals(that.ordering);
    }
    return false;
  }

  @Override
  public int hashCode() {
    return ordering.hashCode() ^ -921210296; // meaningless
  }

  @Override

    checkNotNull(callable);
    checkNotNull(listeningExecutorService);
    return () -> listeningExecutorService.submit(callable);
  }

  /**
   * Wraps the given callable such that for the duration of {@link Callable#call} the thread that is
   * running will have the given name.
   *
   * @param callable The callable to wrap
   * @param nameSupplier The supplier of thread names, {@link Supplier#get get} will be called once