});
  }

  static <
          T extends @Nullable Object,
          K extends @Nullable Object,
          V extends @Nullable Object,
          M extends Multimap<K, V>>
      Collector<T, ?, M> flatteningToMultimap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends Stream<? extends V>> valueFunction,
          Supplier<M> multimapSupplier) {

    // ? extends Number
    assertAssignable(new TypeToken<List<N1>>() {}, new TypeToken<List<? extends Number>>() {});
    assertAssignable(new TypeToken<ArrayList<N1>>() {}, new TypeToken<List<? extends Number>>() {});
    assertAssignable(
        new TypeToken<List<? extends N11>>() {}, new TypeToken<List<? extends Number>>() {});
  }

  public <N1 extends Number, N2 extends Number, N11 extends N1>

@ElementTypesAreNonnullByDefault
public class SetGenerators {

  public static class ImmutableSetCopyOfGenerator extends TestStringSetGenerator {
    @Override
    protected Set<String> create(String[] elements) {
      return ImmutableSet.copyOf(elements);
    }
  }

  public static class ImmutableSetUnsizedBuilderGenerator extends TestStringSetGenerator {
    @Override
    protected Set<String> create(String[] elements) {

   *
   * @since 3.0
   */
  public static <E extends @Nullable Object> SetView<E> symmetricDifference(
      final Set<? extends E> set1, final Set<? extends E> set2) {
    checkNotNull(set1, "set1");
    checkNotNull(set2, "set2");

    return new SetView<E>() {
      @Override
      public UnmodifiableIterator<E> iterator() {
        final Iterator<? extends E> itr1 = set1.iterator();

            throw new DictionaryException("Failed to access dictionaries", e);
        }
    }

    public OptionalEntity<DictionaryFile<? extends DictionaryItem>> getDictionaryFile(final String id) {
        for (final DictionaryFile<? extends DictionaryItem> dictFile : getDictionaryFiles()) {
            if (dictFile.getId().equals(id)) {
                return OptionalEntity.of(dictFile);
            }
        }

   */
  public static <A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object>
      Function<A, C> compose(Function<B, C> g, Function<A, ? extends B> f) {
    return new FunctionComposition<>(g, f);
  }

  private static class FunctionComposition<
          A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object>
      implements Function<A, C>, Serializable {

      return copyOf(table.cellSet());
    }
  }

  static <R, C, V> ImmutableTable<R, C, V> copyOf(
      Iterable<? extends Cell<? extends R, ? extends C, ? extends V>> cells) {
    ImmutableTable.Builder<R, C, V> builder = ImmutableTable.builder();
    for (Cell<? extends R, ? extends C, ? extends V> cell : cells) {
      builder.put(cell);
    }
    return builder.build();
  }

  /**

      Iterable<? extends Entry<? extends K, ? extends V>> entries) {
    return new Builder<K, V>().putAll(entries).build();
  }

  /** Creates an ImmutableSetMultimap from an asMap.entrySet. */
  static <K, V> ImmutableSetMultimap<K, V> fromMapEntries(
      Collection<? extends Map.Entry<? extends K, ? extends Collection<? extends V>>> mapEntries,

  public static <E extends @Nullable Object> Set<E> copyToSet(Iterable<? extends E> elements) {
    Set<E> set = new LinkedHashSet<>();
    addAll(set, elements);
    return set;
  }

  public static <E extends @Nullable Object> Set<E> copyToSet(E[] elements) {
    return copyToSet(Arrays.asList(elements));
  }

  // Would use Maps.immutableEntry

    public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
      return put(entry.getKey(), entry.getValue());
    }

    /**
     * Adds entries to the built multimap.
     *
     * @since 19.0
     */
    @CanIgnoreReturnValue
    public Builder<K, V> putAll(Iterable<? extends Entry<? extends K, ? extends V>> entries) {
      for (Entry<? extends K, ? extends V> entry : entries) {
        put(entry);