initMultimapWithNullKey();
    assertTrue(multimap().keySet().contains(null));
  }

  @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
  public void testKeySetContainsNullKeyAbsent() {
    assertFalse(multimap().keySet().contains(null));
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testKeySetRemovePropagatesToMultimap() {
    int key0Count = multimap().get(k0()).size();

   * key-value mapping appears multiple times in the input multimap, it only appears once in the
   * constructed multimap.
   *
   * <p>You may also consider the equivalent {@code
   * MultimapBuilder.hashKeys().hashSetValues().build(multimap)}, which provides more control over
   * the underlying data structure.
   *

  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)

  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)

  }

  private ArrayListMultimap(Multimap<? extends K, ? extends V> multimap) {
    this(
        multimap.keySet().size(),
        (multimap instanceof ArrayListMultimap)
            ? ((ArrayListMultimap<?, ?>) multimap).expectedValuesPerKey
            : DEFAULT_VALUES_PER_KEY);
    putAll(multimap);
  }

  /**

   */
  static <K extends @Nullable Object, V extends @Nullable Object> void writeMultimap(
      Multimap<K, V> multimap, ObjectOutputStream stream) throws IOException {
    stream.writeInt(multimap.asMap().size());
    for (Map.Entry<K, Collection<V>> entry : multimap.asMap().entrySet()) {
      stream.writeObject(entry.getKey());
      stream.writeInt(entry.getValue().size());

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAllAbsentKey() {
    assertEmpty(multimap().removeAll(k3()));
    expectUnchanged();
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAllPresentKey() {
    assertContentsAnyOrder(multimap().removeAll(k0()), v0());
    expectMissing(e0());
  }

    TreeMultimap<String, Integer> multimap = TreeMultimap.create();
    multimap.put("google", 2);
    multimap.put("google", 6);
    multimap.put("foo", 3);
    multimap.put("foo", 1);
    multimap.put("foo", 7);
    multimap.put("tree", 4);
    multimap.put("tree", 0);
    return multimap;
  }

  public void testToString() {
    SetMultimap<String, Integer> multimap = create();

    for (Collection<V> valueCollection : multimap().asMap().values()) {
      SortedSet<V> valueSet = (SortedSet<V>) valueCollection;
      assertEquals(multimap().valueComparator(), valueSet.comparator());
    }
  }

  public void testAsMapGetImplementsSortedSet() {
    for (K key : multimap().keySet()) {
      SortedSet<V> valueSet = (SortedSet<V>) multimap().asMap().get(key);

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.Multimap;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;
import org.junit.Ignore;

/**
 * Tester for {@code Multimap.toString()}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible