// Check whether we should ignore everything else and pull from the web.
    if (web) {
      StringBuilder builder = new StringBuilder(length);
      CharSamples sampler = new CharSamples(rand);
      for (int i = 0; i < length; i++) {
        int cp = sampler.nextCodePoint();
        builder.appendCodePoint(cp);
      }
      return builder.toString();
    }

import java.util.List;

/**
 * A generator using sample elements whose hash codes all collide badly.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestCollidingSetGenerator implements TestSetGenerator<Object> {
  @Override
  public SampleElements<Object> samples() {
    return new Colliders();
  }

  @Override

/**
 * Creates collections containing unhashable sample elements, to be tested.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestUnhashableCollectionGenerator<T extends Collection<UnhashableObject>>
    implements TestCollectionGenerator<UnhashableObject> {
  @Override
  public SampleElements<UnhashableObject> samples() {
    return new Unhashables();
  }

  @Override

   */
  private @Nullable Object generate(TypeToken<?> type) {
    Class<?> rawType = type.getRawType();
    List<Object> samples = sampleInstances.get(rawType);
    Object sample = pickInstance(samples, null);
    if (sample != null) {
      return sample;
    }
    if (rawType.isEnum()) {
      return pickInstance(rawType.getEnumConstants(), null);
    }
    if (type.isArray()) {

    }

    @Override
    public SampleElements<Entry<V, K>> samples() {
      SampleElements<Entry<K, V>> samples = generator.samples();
      return new SampleElements<>(
          reverse(samples.e0()),
          reverse(samples.e1()),
          reverse(samples.e2()),
          reverse(samples.e3()),
          reverse(samples.e4()));
    }

    private Entry<V, K> reverse(Entry<K, V> entry) {

  @CollectionSize.Require(absent = ZERO)
  public void testRemoveIf_sometimesTrue() {
    assertTrue(
        "removeIf(isEqual(present)) should return true",
        collection.removeIf(Predicate.isEqual(samples.e0())));
    expectMissing(samples.e0());
  }

  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveIf_allPresent() {

    }
  }

  public static class ImmutableMapEntryListGenerator
      implements TestListGenerator<Entry<String, Integer>> {

    @Override
    public SampleElements<Entry<String, Integer>> samples() {
      return new SampleElements<>(
          mapEntry("foo", 5),
          mapEntry("bar", 3),
          mapEntry("baz", 17),
          mapEntry("quux", 1),
          mapEntry("toaster", -2));
    }

    } catch (IOException | ClassNotFoundException e) {
      Helpers.fail(e, e.getMessage());
    }
    throw new AssertionError("not reachable");
  }

  @Override
  public SampleElements<E> samples() {
    return delegate.samples();
  }

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

  @Override
  public Iterable<E> order(List<E> insertionOrder) {

    private ReserializedSetGenerator(OneSizeTestContainerGenerator<Collection<E>, E> gen) {
      this.gen = gen;
    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public Set<E> create(Object... elements) {
      return (Set<E>) SerializableTester.reserialize(gen.create(elements));
    }

    @Override

    private ReserializedListGenerator(OneSizeTestContainerGenerator<Collection<E>, E> gen) {
      this.gen = gen;
    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public List<E> create(Object... elements) {
      return (List<E>) SerializableTester.reserialize(gen.create(elements));
    }

    @Override