* {@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) {

   * <? extends Object> is mostly the same as <?> to plain Java. But to nullness checkers, they
   * differ: <? extends Object> means "non-null types," while <?> means "all types."
   */
  ImmutableMap<K, V> getAllPresent(Iterable<? extends Object> keys);

  /**
   * Associates {@code value} with {@code key} in this cache. If the cache previously contained a
   * value associated with {@code key}, the old value is replaced by {@code value}.
   *

   * actual implementation tests are further down.
   */

  public abstract static class AbstractFilteredIterableTest<C extends Iterable<Integer>>
      extends TestCase {
    abstract C createUnfiltered(Iterable<Integer> contents);

    abstract C filter(C elements, Predicate<? super Integer> predicate);

    public void testIterationOrderPreserved() {

    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() {

    }

    @Override
    public E[] createArray(int length) {
      return gen.createArray(length);
    }

    @Override
    public Iterable<E> order(List<E> insertionOrder) {
      return gen.order(insertionOrder);
    }
  }

  private static Set<Feature<?>> computeReserializedCollectionFeatures(Set<Feature<?>> features) {

    public NavigableMap<K, V> create(Object... entries) {
      NavigableMap<K, V> map = (NavigableMap<K, V>) delegate.create(entries);
      return map.descendingMap();
    }

    @Override
    public Iterable<Entry<K, V>> order(List<Entry<K, V>> insertionOrder) {
      insertionOrder = castOrCopyToList(delegate.order(insertionOrder));
      reverse(insertionOrder);
      return insertionOrder;
    }

    }

    @Override
    public E[] createArray(int length) {
      return gen.createArray(length);
    }

    @Override
    public Iterable<E> order(List<E> insertionOrder) {
      return gen.order(insertionOrder);
    }
  }

  private static Set<Feature<?>> computeReserializedCollectionFeatures(Set<Feature<?>> features) {

  private static final DenseImmutableTable<Character, Integer, String> DENSE =
      new DenseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  @Override
  Iterable<ImmutableTable<Character, Integer, String>> getTestInstances() {
    return ImmutableList.<ImmutableTable<Character, Integer, String>>of(SPARSE, DENSE);
  }

  public void testCellSet() {

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

  /**
   * {@inheritDoc}
   *
   * <p>Though the method signature doesn't say so explicitly, the returned map has {@link Set}

  }

  private final class AsMapOfRanges extends IteratorBasedAbstractMap<Range<K>, V> {

    final Iterable<Entry<Range<K>, V>> entryIterable;

    @SuppressWarnings("unchecked") // it's safe to upcast iterables
    AsMapOfRanges(Iterable<RangeMapEntry<K, V>> entryIterable) {
      this.entryIterable = (Iterable) entryIterable;
    }

    @Override
    public boolean containsKey(@Nullable Object key) {