// ? 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>

   *
   * @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();

  interface StrongValueEntry<K, V, E extends InternalEntry<K, V, E>>
      extends InternalEntry<K, V, E> {}

  /** Marker interface for {@link InternalEntry} implementations for weak values. */
  interface WeakValueEntry<K, V, E extends InternalEntry<K, V, E>> extends InternalEntry<K, V, E> {
    /** Gets the weak value reference held by entry. */

  }

  static <R extends @Nullable Object, C extends @Nullable Object, V extends @Nullable Object>
      Table<R, C, V> table(Table<R, C, V> table, @CheckForNull Object mutex) {
    return new SynchronizedTable<>(table, mutex);
  }

  static final class SynchronizedTable<
          R extends @Nullable Object, C extends @Nullable Object, V extends @Nullable Object>

  @Beta // TODO: b/288085449 - Remove.
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(
          Comparator<? super K> comparator,
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableSortedMap(comparator, keyFunction, valueFunction);

    // ? 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>

     * operation O(1).
     */

    @CheckForNull private Iterator<? extends Iterator<? extends T>> topMetaIterator;

    // Only becomes nonnull if we encounter nested concatenations.
    @CheckForNull private Deque<Iterator<? extends Iterator<? extends T>>> metaIterators;

    ConcatenatedIterator(Iterator<? extends Iterator<? extends T>> metaIterator) {
      iterator = emptyIterator();

tDownloader$1.class package org.apache.maven.wrapper; synchronized class DefaultDownloader$1 extends java.net.Authenticator { void DefaultDownloader$1(DefaultDownloader); protected java.net.PasswordAuthenticati getPasswordAuthentic(); } org/apache/maven/wrapper/DefaultDownloader$SystemPropertiesProx.class package org.apache.maven.wrapper; synchronized class DefaultDownloader$SystemPropertiesProx extends java.net.Authenticator { private void DefaultDownloader$SystemPropertiesProx(); protected jav...

   * throws an {@code IllegalStateException}.)
   *
   * @since 21.0
   */
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(
          Comparator<? super K> comparator,
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableSortedMap(comparator, keyFunction, valueFunction);

  public static <
          T extends @Nullable Object,
          K extends @Nullable Object,
          V extends @Nullable Object,
          M extends Multimap<K, V>>
      Collector<T, ?, M> flatteningToMultimap(
          java.util.function.Function<? super T, ? extends K> keyFunction,
          java.util.function.Function<? super T, ? extends Stream<? extends V>> valueFunction,