K[] createKeyArray(int length);

  V[] createValueArray(int length);

  SampleElements<K> sampleKeys();

  SampleElements<V> sampleValues();

  Collection<V> createCollection(Iterable<? extends V> values);

import com.google.common.collect.ListMultimap;
import com.google.common.collect.testing.features.MapFeature;
import java.util.List;
import org.junit.Ignore;

/**
 * Testers for {@link ListMultimap#replaceValues(Object, Iterable)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

  }

  public void testPresentInstances_callingIteratorTwice() {
    List<Optional<String>> optionals =
        ImmutableList.of(Optional.of("a"), Optional.<String>absent(), Optional.of("c"));
    Iterable<String> onlyPresent = Optional.presentInstances(optionals);
    assertThat(onlyPresent).containsExactly("a", "c").inOrder();
    assertThat(onlyPresent).containsExactly("a", "c").inOrder();
  }

   */
  protected abstract T create(UnhashableObject[] elements);

  @Override
  public UnhashableObject[] createArray(int length) {
    return new UnhashableObject[length];
  }

  @Override
  public Iterable<UnhashableObject> order(List<UnhashableObject> insertionOrder) {
    return insertionOrder;
  }

  /**
   * Returns {@code true} if {@code elements} is a sorted collection using an ordering equivalent to
   * {@code comparator}.
   */
  public static boolean hasSameComparator(Comparator<?> comparator, Iterable<?> elements) {
    checkNotNull(comparator);
    checkNotNull(elements);
    Comparator<?> comparator2;
    if (elements instanceof SortedSet) {
      comparator2 = comparator((SortedSet<?>) elements);

   * values} is a {@link Collection}. Otherwise it creates a {@link #builder} and uses {@link
   * Builder#addAll(Iterable)}, with all the performance implications associated with that.
   */
  public static ImmutableIntArray copyOf(Iterable<Integer> values) {
    if (values instanceof Collection) {
      return copyOf((Collection<Integer>) values);
    }
    return builder().addAll(values).build();

   * <? 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}.
   *

import com.google.common.collect.ListMultimap;
import com.google.common.collect.testing.features.MapFeature;
import java.util.List;
import org.junit.Ignore;

/**
 * Testers for {@link ListMultimap#putAll(Object, Iterable)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")

   */
  protected abstract T create(UnhashableObject[] elements);

  @Override
  public UnhashableObject[] createArray(int length) {
    return new UnhashableObject[length];
  }

  @Override
  public Iterable<UnhashableObject> order(List<UnhashableObject> insertionOrder) {
    return insertionOrder;
  }

  }

  @Override
  public Set<V> removeAll(@CheckForNull Object key) {
    return (Set<V>) super.removeAll(key);
  }

  @Override
  public Set<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {
    return (Set<V>) super.replaceValues(key, values);
  }

  @Override
  Set<Entry<K, V>> createEntries() {
    return Sets.filter(unfiltered().entries(), entryPredicate());
  }