import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.Map;

@GwtCompatible(emulated = true)
abstract class HashMultimapGwtSerializationDependencies<K, V> extends AbstractSetMultimap<K, V> {
  HashMultimapGwtSerializationDependencies(Map<K, Collection<V>> map) {
    super(map);
  }

  K dummyKey;
  V dummyValue;

 *
 * <p>TODO(cpovirk): Consider applying this subclass approach to our other types.
 */
@GwtCompatible(emulated = true)
abstract class HashMultimapGwtSerializationDependencies<K, V> extends AbstractSetMultimap<K, V> {
  HashMultimapGwtSerializationDependencies(Map<K, Collection<V>> map) {
    super(map);
  }

 * @since 2.0
 */
@GwtCompatible(serializable = true, emulated = true)
@ElementTypesAreNonnullByDefault
public final class HashMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends HashMultimapGwtSerializationDependencies<K, V> {
  private static final int DEFAULT_VALUES_PER_KEY = 2;

  @VisibleForTesting transient int expectedValuesPerKey = DEFAULT_VALUES_PER_KEY;

  /**