public void testAsMapValuesImplementList() {
    for (Collection<V> valueCollection : multimap().asMap().values()) {
      assertTrue(valueCollection instanceof List);
    }
  }

  public void testAsMapGetImplementsList() {
    for (K key : multimap().keySet()) {
      assertTrue(multimap().asMap().get(key) instanceof List);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

import com.google.common.collect.Multimap;

/**
 * Helper methods/assertions for use with {@code com.google.common.collect} types.
 *
 * @author Colin Decker
 */
@GwtCompatible
final class GoogleHelpers {

  private GoogleHelpers() {}

  static void assertEmpty(Multimap<?, ?> multimap) {
    if (!multimap.isEmpty()) {
      fail("Not true that " + multimap + " is empty");
    }
  }

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MultimapContainsValueTester<K, V>
    extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  @CollectionSize.Require(absent = ZERO)
  public void testContainsValueYes() {
    assertTrue(multimap().containsValue(v0()));
  }

  public void testContainsValueNo() {
    assertFalse(multimap().containsValue(v3()));
  }

  @MapFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)

    return super.asMap();
  }

  /**
   * Stores a key-value pair in the multimap.
   *
   * @param key key to store in the multimap
   * @param value value to store in the multimap
   * @return {@code true} if the method increased the size of the multimap, or {@code false} if the
   *     multimap already contained the key-value pair
   */
  @CanIgnoreReturnValue
  @Override

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MultimapContainsValueTester<K, V>
    extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  @CollectionSize.Require(absent = ZERO)
  public void testContainsValueYes() {
    assertTrue(multimap().containsValue(v0()));
  }

  public void testContainsValueNo() {
    assertFalse(multimap().containsValue(v3()));
  }

  @MapFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)

    assertEqualInOrder(values, multimap().get(key));

    if (!values.isEmpty()) {
      assertEqualInOrder(values, multimap().asMap().get(key));
      assertFalse(multimap().isEmpty());
    } else {
      assertNull(multimap().asMap().get(key));
    }

    assertEquals(values.size(), multimap().get(key).size());
    assertEquals(values.size() > 0, multimap().containsKey(key));

  public enum ListMultimapImpl {
    ArrayListMultimapImpl {
      @Override
      <K, V> ListMultimap<K, V> create(Multimap<K, V> contents) {
        return ArrayListMultimap.create(contents);
      }
    },
    LinkedListMultimapImpl {
      @Override
      <K, V> ListMultimap<K, V> create(Multimap<K, V> contents) {
        return LinkedListMultimap.create(contents);
      }
    },
    ImmutableListMultimapImpl {

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MultimapForEachTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  public void testForEach() {
    List<Entry<K, V>> entries = new ArrayList<>();
    multimap().forEach((k, v) -> entries.add(mapEntry(k, v)));
    assertEqualIgnoringOrder(getSampleElements(), multimap().entries());
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testForEachOrder() {

  public void testPutDuplicateValue() {
    List<Entry<K, V>> entries = copyToList(multimap().entries());

    for (Entry<K, V> entry : entries) {
      resetContainer();

      K k = entry.getKey();
      V v = entry.getValue();

      List<V> values = multimap().get(k);
      List<V> expectedValues = copyToList(values);

      assertTrue(multimap().put(k, v));
      expectedValues.add(v);
      assertGet(k, expectedValues);

@GwtCompatible
public enum MultimapFeature implements Feature<Multimap> {
  VALUE_COLLECTIONS_SUPPORT_ITERATOR_REMOVE;

  private final Set<Feature<? super Multimap>> implied;

  MultimapFeature(Feature<? super Multimap>... implied) {
    this.implied = copyToSet(implied);
  }

  @Override
  public Set<Feature<? super Multimap>> getImpliedFeatures() {
    return implied;
  }