/**
 * Basic implementation of the {@link ListMultimap} interface. It's a wrapper around {@link
 * AbstractMapBasedMultimap} that converts the returned collections into {@code Lists}. The {@link
 * #createCollection} method must return a {@code List}.
 *
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible
abstract class AbstractListMultimap<K extends @Nullable Object, V extends @Nullable Object>

/**
 * Basic implementation of the {@link SetMultimap} interface. It's a wrapper around {@link
 * AbstractMapBasedMultimap} that converts the returned collections into {@code Sets}. The {@link
 * #createCollection} method must return a {@code Set}.
 *
 * @author Jared Levy
 */
@GwtCompatible
abstract class AbstractSetMultimap<K extends @Nullable Object, V extends @Nullable Object>

   */
  @Override
  SortedSet<V> createCollection() {
    return new TreeSet<>(valueComparator);
  }

  @Override
  Collection<V> createCollection(@ParametricNullness K key) {
    if (key == null) {
      int unused = keyComparator().compare(key, key);
    }
    return super.createCollection(key);
  }

  /**
   * Returns the comparator that orders the multimap keys.

  K[] createKeyArray(int length);

  V[] createValueArray(int length);

  SampleElements<K> sampleKeys();

  SampleElements<V> sampleValues();

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

  K[] createKeyArray(int length);

  V[] createValueArray(int length);

  SampleElements<K> sampleKeys();

  SampleElements<V> sampleValues();

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

  }

  @Override
  public SampleElements<String> sampleValues() {
    return new SampleElements<>("January", "February", "March", "April", "May");
  }

  @Override
  public Collection<String> createCollection(Iterable<? extends String> values) {
    return copyToList(values);
  }

  @Override
  public final ListMultimap<String, String> create(Object... entries) {
    @SuppressWarnings("unchecked")

  }

  @Override
  public SampleElements<String> sampleValues() {
    return new SampleElements<>("January", "February", "March", "April", "May");
  }

  @Override
  public Collection<String> createCollection(Iterable<? extends String> values) {
    return copyToList(values);
  }

  @Override
  public final ListMultimap<String, String> create(Object... entries) {
    @SuppressWarnings("unchecked")

  }

  @Override
  public SampleElements<String> sampleValues() {
    return new SampleElements<>("January", "February", "March", "April", "May");
  }

  @Override
  public Collection<String> createCollection(Iterable<? extends String> values) {
    return copyToSet(values);
  }

  @Override
  public final SetMultimap<String, String> create(Object... entries) {
    @SuppressWarnings("unchecked")

            : DEFAULT_VALUES_PER_KEY);
    putAll(multimap);
  }

  /**
   * Creates a new, empty {@code ArrayList} to hold the collection of values for an arbitrary key.
   */
  @Override
  List<V> createCollection() {
    return new ArrayList<>(expectedValuesPerKey);
  }

  /**
   * Reduces the memory used by this {@code ArrayListMultimap}, if feasible.
   *