super(5, MODIFIABLE, newArrayList(1, 2), IteratorTester.KnownOrder.KNOWN_ORDER);
    }
  }

  private static Iterator<Integer> iterateOver(int... values) {
    // Note: Ints.asList's iterator does not support remove which we need for testing.
    return new ArrayList<>(Ints.asList(values)).iterator();
  }

  public void testElementsEqual() {
    Iterable<?> a;
    Iterable<?> b;

    // Base case.

   * lesser. For example, {@code [] < [1.0] < [1.0, 2.0] < [2.0]}.
   *
   * <p>The returned comparator is inconsistent with {@link Object#equals(Object)} (since arrays
   * support only identity equality), but it is consistent with {@link Arrays#equals(double[],
   * double[])}.
   *
   * @since 2.0
   */
  public static Comparator<double[]> lexicographicalComparator() {

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A comparator, with additional methods to support common operations. This is an "enriched" version
 * of {@code Comparator} for pre-Java-8 users, in the same sense that {@link FluentIterable} is an
 * enriched {@link Iterable} for pre-Java-8 users.
 *

   * lesser. For example, {@code [] < [1.0f] < [1.0f, 2.0f] < [2.0f]}.
   *
   * <p>The returned comparator is inconsistent with {@link Object#equals(Object)} (since arrays
   * support only identity equality), but it is consistent with {@link Arrays#equals(float[],
   * float[])}.
   *
   * @since 2.0
   */
  public static Comparator<float[]> lexicographicalComparator() {

    throw new UnsupportedOperationException();
  }

  /**
   * Not supported. This method exists only to hide {@link ImmutableSet#builderWithExpectedSize}
   * from consumers of {@code ImmutableSortedSet}.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Not supported by ImmutableSortedSet.
   */
  @DoNotCall("Use naturalOrder (which does not accept an expected size)")

                return Sets.filter(unfiltered, Collections2Test.NOT_YYY_ZZZ);
              }
            })
        .named("Sets.filter")
        .withFeatures(
            CollectionFeature.SUPPORTS_ADD,
            CollectionFeature.SUPPORTS_REMOVE,
            CollectionFeature.ALLOWS_NULL_VALUES,
            CollectionFeature.KNOWN_ORDER,
            CollectionSize.ANY)
        .createTestSuite();
  }

  @J2ktIncompatible

    // bytes when the both the map and its keySet or value collection are written to the same
    // instance of ObjectOutputStream.

    // TODO(b/160980469): remove support for the old serialization format after some time
    private static final boolean USE_LEGACY_SERIALIZATION = true;

    private final Object keys;
    private final Object values;

 * (The same goes for the message-accepting overloads.)
 *
 * <h3>Only {@code %s} is supported</h3>
 *
 * <p>{@code Preconditions} uses {@link Strings#lenientFormat} to format error message template
 * strings. This only supports the {@code "%s"} specifier, not the full range of {@link
 * java.util.Formatter} specifiers. However, note that if the number of arguments does not match the

    assertFalse(unmod.keys().contains("pwnd"));
  }

  /**
   * The supplied multimap will be mutated and an unmodifiable instance used in its stead. The
   * multimap must support null keys and values.
   */
  private static void checkUnmodifiableMultimap(
      Multimap<@Nullable String, @Nullable Integer> multimap, boolean permitsDuplicates) {

  }

  /**
   * Returns the empty immutable multiset.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked") // all supported methods are covariant
  public static <E> ImmutableMultiset<E> of() {
    return (ImmutableMultiset<E>) RegularImmutableMultiset.EMPTY;
  }

  /**
   * Returns an immutable multiset containing a single element.