*
 * @author Kevin Bourrillion
 * @author Jared Levy
 * @author Chris Povirk
 * @since 2.0
 */
@GwtCompatible
public final class Sets {
  private Sets() {}

  /**
   * {@link AbstractSet} substitute without the potentially-quadratic {@code removeAll}
   * implementation.
   */
  abstract static class ImprovedAbstractSet<E extends @Nullable Object> extends AbstractSet<E> {
    @Override

   * advantage of <a
   * href="https://docs.oracle.com/javase/tutorial/java/generics/genTypeInference.html#type-inference-instantiation">"diamond"
   * syntax</a>.
   */
  @SuppressWarnings("NonApiType") // acts as a direct substitute for a constructor call
  public static <E extends @Nullable Object> ArrayList<E> newArrayList() {
    return new ArrayList<>();
  }

  /**

   * advantage of <a
   * href="https://docs.oracle.com/javase/tutorial/java/generics/genTypeInference.html#type-inference-instantiation">"diamond"
   * syntax</a>.
   */
  @SuppressWarnings("NonApiType") // acts as a direct substitute for a constructor call
  public static <E extends @Nullable Object> ArrayList<E> newArrayList() {
    return new ArrayList<>();
  }

  /**

 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 * @author Chris Povirk
 * @since 2.0
 */
@GwtCompatible
public final class Sets {
  private Sets() {}

  /**
   * {@link AbstractSet} substitute without the potentially-quadratic {@code removeAll}
   * implementation.
   */
  abstract static class ImprovedAbstractSet<E extends @Nullable Object> extends AbstractSet<E> {
    @Override

    assertThat(map.put(one, two)).isNull();

    assertThat(map).containsEntry(three, one);
    assertThat(map).containsEntry(one, two);

    // TODO(cgruber): Confirm with fry@ that this is a reasonable substitute.
    // Set<Entry<Object, Object>> entries = map.entrySet();
    // assertThat(entries).containsExactly(
    //    Maps.immutableEntry(three, one), Maps.immutableEntry(one, two));
    // Set<Object> keys = map.keySet();

    assertThat(map.put(one, two)).isNull();

    assertThat(map).containsEntry(three, one);
    assertThat(map).containsEntry(one, two);

    // TODO(cgruber): Confirm with fry@ that this is a reasonable substitute.
    // Set<Entry<Object, Object>> entries = map.entrySet();
    // assertThat(entries).containsExactly(
    //    Maps.immutableEntry(three, one), Maps.immutableEntry(one, two));
    // Set<Object> keys = map.keySet();

   * syntax</a>.
   *
   * @return a new, empty {@code HashMap}
   */
  @SuppressWarnings("NonApiType") // acts as a direct substitute for a constructor call
  public static <K extends @Nullable Object, V extends @Nullable Object>
      HashMap<K, V> newHashMap() {
    return new HashMap<>();
  }

  /**

   * syntax</a>.
   *
   * @return a new, empty {@code HashMap}
   */
  @SuppressWarnings("NonApiType") // acts as a direct substitute for a constructor call
  public static <K extends @Nullable Object, V extends @Nullable Object>
      HashMap<K, V> newHashMap() {
    return new HashMap<>();
  }

  /**

    ImmutableList<Service> copy = ImmutableList.copyOf(services);
    if (copy.isEmpty()) {
      // Having no services causes the manager to behave strangely. Notably, listeners are never
      // fired. To avoid this we substitute a placeholder service.
      logger
          .get()
          .log(
              Level.WARNING,
              "ServiceManager configured with no services.  Is your application configured"

    TypeToken<Map<String, Integer>> reserialized =
        reserialize(new TypeToken<Map<String, Integer>>() {});
    assertEquals(reserialized, substitute(reserialized, String.class));
  }

  private static <T, X> TypeToken<T> substitute(TypeToken<T> type, Class<X> arg) {
    return type.where(new TypeParameter<X>() {}, arg);
  }

  @SuppressWarnings("ClassCanBeStatic") // We want to test an inner class.