return super.containsAll(targets);
    }

    /*
     * If targets is a sorted set with the same comparator, containsAll can run
     * in O(n) time stepping through the two collections.
     */
    Iterator<E> thisIterator = iterator();

    Iterator<?> thatIterator = targets.iterator();
    // known nonempty since we checked targets.size() > 1

    if (!thisIterator.hasNext()) {

  }

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && delegate.contains(object);
  }

  @Override
  public boolean containsAll(Collection<?> targets) {
    return delegate.containsAll(targets);
  }

  @Override
  public int size() {
    return delegate.size();
  }

  @Override
  public boolean isEmpty() {
    return delegate.isEmpty();
  }

  @Override

/**
 * Unit test for {@link AppendableWriter}.
 *
 * @author Alan Green
 */
public class AppendableWriterTest extends IoTestCase {

  /** Helper class for testing behavior with Flushable and Closeable targets. */
  private static class SpyAppendable implements Appendable, Flushable, Closeable {
    boolean flushed;
    boolean closed;
    StringBuilder result = new StringBuilder();

    @Override

  }

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && delegate.contains(object);
  }

  @Override
  public boolean containsAll(Collection<?> targets) {
    return delegate.containsAll(targets);
  }

  public int size() {
    return delegate.size();
  }

  @Override
  public boolean isEmpty() {
    return delegate.isEmpty();
  }

  @Override

  @Override
  int indexOf(@CheckForNull Object target) {
    if (!contains(target)) {
      return -1;
    }
    // The cast is safe because of the contains check—at least for any reasonable Comparable class.
    @SuppressWarnings("unchecked")
    // requireNonNull is safe because of the contains check.
    C c = (C) requireNonNull(target);
    return (int) domain.distance(first(), c);
  }

  @Override

  @Override
  public boolean containsAll(Collection<?> targets) {
    for (Object target : targets) {
      if (target == null) {
        // This set never contains null.  We need to explicitly check here
        // because some comparator might throw NPE (e.g. the natural ordering).
        return false;
      }
    }
    try {
      return sortedDelegate.containsAll(targets);
    } catch (ClassCastException e) {

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && delegateList().contains(object);
  }

  @Override
  public boolean containsAll(Collection<?> targets) {
    return delegateList().containsAll(targets);
  }

  public int size() {
    return delegateList().size();
  }

  @Override
  public boolean isEmpty() {
    return delegateList().isEmpty();
  }

  @Override

/**
 * Unit test for {@link AppendableWriter}.
 *
 * @author Alan Green
 */
public class AppendableWriterTest extends IoTestCase {

  /** Helper class for testing behavior with Flushable and Closeable targets. */
  private static class SpyAppendable implements Appendable, Flushable, Closeable {
    boolean flushed;
    boolean closed;
    StringBuilder result = new StringBuilder();

    @Override

    @Override
    public boolean contains(@CheckForNull Object target) {
      return indexOf(target) >= 0;
    }

    @Override
    public int indexOf(@CheckForNull Object target) {
      return target instanceof Integer ? parent.indexOf((Integer) target) : -1;
    }

    @Override
    public int lastIndexOf(@CheckForNull Object target) {
      return target instanceof Integer ? parent.lastIndexOf((Integer) target) : -1;

    @Override
    public boolean contains(@CheckForNull Object target) {
      return indexOf(target) >= 0;
    }

    @Override
    public int indexOf(@CheckForNull Object target) {
      return target instanceof Double ? parent.indexOf((Double) target) : -1;
    }

    @Override
    public int lastIndexOf(@CheckForNull Object target) {
      return target instanceof Double ? parent.lastIndexOf((Double) target) : -1;
    }