"[" + e0() + "]",
        collection.toString());
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(value = KNOWN_ORDER, absent = NON_STANDARD_TOSTRING)
  public void testToString_sizeSeveral() {
    String expected = copyToList(getOrderedElements()).toString();
    assertEquals("collection.toString() incorrect", expected, collection.toString());
  }

  @CollectionSize.Require(absent = ZERO)

   *     to primitives
   * @throws NullPointerException if {@code collection} or any of its elements is null
   * @since 1.0 (parameter was {@code Collection<Double>} before 12.0)
   */
  public static double[] toArray(Collection<? extends Number> collection) {
    if (collection instanceof DoubleArrayAsList) {
      return ((DoubleArrayAsList) collection).toDoubleArray();
    }

   * the {@link Multimap} interface.
   */
  @Override
  List<V> get(@ParametricNullness K key);

  /**
   * {@inheritDoc}
   *
   * <p>Because the values for a given key may have duplicates and follow the insertion ordering,
   * this method returns a {@link List}, instead of the {@link java.util.Collection} specified in
   * the {@link Multimap} interface.

   * the {@link Multimap} interface.
   */
  @Override
  List<V> get(@ParametricNullness K key);

  /**
   * {@inheritDoc}
   *
   * <p>Because the values for a given key may have duplicates and follow the insertion ordering,
   * this method returns a {@link List}, instead of the {@link java.util.Collection} specified in
   * the {@link Multimap} interface.

  }

  @Override
  public <T extends @Nullable Object> List<Future<T>> invokeAll(
      Collection<? extends Callable<T>> tasks) throws InterruptedException {
    return delegate().invokeAll(tasks);
  }

  @Override
  public <T extends @Nullable Object> List<Future<T>> invokeAll(
      Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
      throws InterruptedException {

    Helpers.assertEqualIgnoringOrder(getSampleElements(), asList(collection.stream().toArray()));
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testStreamToArrayKnownOrder() {
    assertEquals(getOrderedElements(), asList(collection.stream().toArray()));
  }

  public void testStreamCount() {
    assertEquals(getNumElements(), collection.stream().count());
  }

  }

  private static <E> ImmutableList<E> copyFromCollection(Collection<? extends E> collection) {
    Object[] elements = collection.toArray();
    switch (elements.length) {
      case 0:
        return of();
      case 1:
        @SuppressWarnings("unchecked") // safe because it came from `collection`
        E element = (E) elements[0];
        return of(element);
      default:

  }

  private void assertCollectionSize(Collection<?> collection, int size) {
    assertEquals(size, collection.size());
    if (size > 0) {
      assertFalse(collection.isEmpty());
    } else {
      assertTrue(collection.isEmpty());
    }
    assertEquals(size, Iterables.size(collection));
    assertEquals(size, Iterators.size(collection.iterator()));
  }

  static boolean removeAllImpl(Multiset<?> self, Collection<?> elementsToRemove) {
    Collection<?> collection =
        (elementsToRemove instanceof Multiset)
            ? ((Multiset<?>) elementsToRemove).elementSet()
            : elementsToRemove;

    return self.elementSet().removeAll(collection);
  }

  /** An implementation of {@link Multiset#retainAll}. */

    super(Platform.<K, Collection<V>>newHashMapWithExpectedSize(expectedKeys));
    Preconditions.checkArgument(expectedValuesPerKey >= 0);
    this.expectedValuesPerKey = expectedValuesPerKey;
  }

  private HashMultimap(Multimap<? extends K, ? extends V> multimap) {
    super(Platform.<K, Collection<V>>newHashMapWithExpectedSize(multimap.keySet().size()));
    putAll(multimap);
  }