public abstract class ForwardingImmutableSet<E> extends ImmutableSet<E> {
  private final transient Set<E> delegate;

  ForwardingImmutableSet(Set<E> delegate) {
    // TODO(cpovirk): are we over-wrapping?
    this.delegate = Collections.unmodifiableSet(delegate);
  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    return Iterators.unmodifiableIterator(delegate.iterator());
  }

  @Override

 * wrap} tasks before they are submitted to the underlying executor.
 *
 * <p>Note that task wrapping may occur even if the task is never executed.
 *
 * <p>For delegation without task-wrapping, see {@link ForwardingExecutorService}.
 *
 * @author Chris Nokleberg
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault

    assertThrows(IOException.class, () -> reader.mark(10));

    assertThrows(IOException.class, () -> reader.reset());
  }

  /**
   * Creates a CharSequenceReader wrapping the given CharSequence and tests that the reader produces
   * the same sequence when read using each type of read method it provides.
   */

    assertEquals(65536, replacementArray.length);
    // The final element should always be non-null.
    assertNotNull(replacementArray[replacementArray.length - 1]);
    // Exhaustively check all mappings (an int index avoids wrapping).
    for (int n = 0; n < replacementArray.length; ++n) {
      char c = (char) n;
      if (replacementArray[n] != null) {
        assertEquals(map.get(c), new String(replacementArray[n]));
      } else {

/**
 * An abstract {@code ScheduledExecutorService} that allows subclasses to {@linkplain
 * #wrapTask(Callable) wrap} tasks before they are submitted to the underlying executor.
 *
 * <p>Note that task wrapping may occur even if the task is never executed.
 *
 * @author Luke Sandberg
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault

   */

  @Override
  public void write(char[] cbuf, int off, int len) throws IOException {
    checkNotClosed();
    // It turns out that creating a new String is usually as fast, or faster
    // than wrapping cbuf in a light-weight CharSequence.
    target.append(new String(cbuf, off, len));
  }

  /*
   * Override a few functions for performance reasons to avoid creating unnecessary strings.
   */

  @Override

@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class CharSequenceReader extends Reader {

  @CheckForNull private CharSequence seq;
  private int pos;
  private int mark;

  /** Creates a new reader wrapping the given character sequence. */
  public CharSequenceReader(CharSequence seq) {
    this.seq = checkNotNull(seq);
  }

  private void checkOpen() throws IOException {
    if (seq == null) {

  private final List<E> delegate;
  @Nullable E forSerialization;

  RegularImmutableList(List<E> delegate) {
    // TODO(cpovirk): avoid redundant unmodifiableList wrapping
    this.delegate = unmodifiableList(delegate);
  }

  @Override
  List<E> delegateList() {
    return delegate;
  }

    assertThrows(IOException.class, () -> reader.mark(10));

    assertThrows(IOException.class, () -> reader.reset());
  }

  /**
   * Creates a CharSequenceReader wrapping the given CharSequence and tests that the reader produces
   * the same sequence when read using each type of read method it provides.
   */

    assertEquals(65536, replacementArray.length);
    // The final element should always be non-null.
    assertNotNull(replacementArray[replacementArray.length - 1]);
    // Exhaustively check all mappings (an int index avoids wrapping).
    for (int n = 0; n < replacementArray.length; ++n) {
      char c = (char) n;
      if (replacementArray[n] != null) {
        assertEquals(map.get(c), new String(replacementArray[n]));
      } else {