public EquivalenceTester<T> addEquivalenceGroup(T first, T... rest) {
    addEquivalenceGroup(Lists.asList(first, rest));
    return this;
  }

  @CanIgnoreReturnValue
  public EquivalenceTester<T> addEquivalenceGroup(Iterable<T> group) {
    delegate.addRelatedGroup(group);
    items.addAll(ImmutableList.copyOf(group));
    return this;
  }

  /** Run tests on equivalence methods, throwing a failure on an invalid test */

    runIteratorTest(UNMODIFIABLE, IteratorTester.KnownOrder.UNKNOWN_ORDER, getSampleElements());
  }

  private void runIteratorTest(
      Set<IteratorFeature> features, IteratorTester.KnownOrder knownOrder, Iterable<E> elements) {
    new IteratorTester<E>(
        Platform.collectionIteratorTesterNumIterations(), features, elements, knownOrder) {
      @Override
      protected Iterator<E> newTargetIterator() {

 *
 * {@snippet :
 * class MySubtypeTests extends SubtypeTester {
 *   @TestSubtype(suppressGetSubtype = true, suppressGetSupertype = true)
 *   public <T> Iterable<? extends T> listIsSubtypeOfIterable(List<T> list) {
 *     return isSubtype(list);
 *   }
 *
 *   @TestSubtype
 *   public List<String> intListIsNotSubtypeOfStringList(List<Integer> intList) {

   * {@link Predicate#apply}. Do not provide a predicate such as {@code
   * Predicates.instanceOf(ArrayList.class)}, which is inconsistent with equals. (See {@link
   * Iterables#filter(Iterable, Class)} for related functionality.)
   *
   * @since 14.0
   */
  public static <E extends @Nullable Object> Multiset<E> filter(
      Multiset<E> unfiltered, Predicate<? super E> predicate) {

   * {@link Predicate#apply}. Do not provide a predicate such as {@code
   * Predicates.instanceOf(ArrayList.class)}, which is inconsistent with equals. (See {@link
   * Iterables#filter(Iterable, Class)} for related functionality.)
   *
   * @since 14.0
   */
  public static <E extends @Nullable Object> Multiset<E> filter(
      Multiset<E> unfiltered, Predicate<? super E> predicate) {

  /**
   * Returns the first of two given parameters that is not {@code null}, if either is, or otherwise
   * throws a {@link NullPointerException}.
   *
   * <p>To find the first non-null element in an iterable, use {@code Iterables.find(iterable,
   * Predicates.notNull())}. For varargs, use {@code Iterables.find(Arrays.asList(a, b, c, ...),
   * Predicates.notNull())}, static importing as necessary.
   *

                      multimap.put(entry.getKey(), entry.getValue());
                    }
                    return multimap;
                  }

                  @Override
                  public Iterable<Entry<String, String>> order(
                      List<Entry<String, String>> insertionOrder) {
                    return new Ordering<Entry<String, String>>() {
                      @Override

   * both use cases by using @PolyNull. (By contrast, we can't use @PolyNull for our superinterface
   * (`implements Function<@PolyNull A, @PolyNull B>`), at least as far as I know.)
   */
  public Iterable<B> convertAll(Iterable<? extends A> fromIterable) {
    checkNotNull(fromIterable, "fromIterable");
    return () ->
        new Iterator<B>() {
          private final Iterator<? extends A> fromIterator = fromIterable.iterator();

 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public class ComparatorsTest extends TestCase {
  public void testLexicographical() {
    Comparator<String> comparator = Ordering.natural();
    Comparator<Iterable<String>> lexy = Comparators.lexicographical(comparator);

    ImmutableList<String> empty = ImmutableList.of();
    ImmutableList<String> a = ImmutableList.of("a");
    ImmutableList<String> aa = ImmutableList.of("a", "a");

   * Multimap} interface.
   *
   * <p>Any duplicates in {@code values} will be stored in the multimap once.
   */
  @CanIgnoreReturnValue
  @Override
  public SortedSet<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {
    return (SortedSet<V>) super.replaceValues(key, values);
  }

  /**
   * Returns a map view that associates each key with the corresponding values in the multimap.