private static final ImmutableSet<Character> ROW_SPACE = ImmutableSet.of('a', 'b');

  private static final ImmutableSet<Integer> COLUMN_SPACE = ImmutableSet.of(1, 2);

  private static final SparseImmutableTable<Character, Integer, String> SPARSE =
      new SparseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  private static final DenseImmutableTable<Character, Integer, String> DENSE =

   *
   * <p>This {@code Collector} uses O(k) memory and takes expected time O(n) (worst-case O(n log
   * k)), as opposed to e.g. {@code Stream.sorted(comparator).limit(k)}, which currently takes O(n
   * log n) time and O(n) space.
   *
   * @throws IllegalArgumentException if {@code k < 0}
   * @since 33.2.0 (available since 22.0 in guava-jre)
   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})

  private static final ImmutableSet<Character> ROW_SPACE = ImmutableSet.of('a', 'b');

  private static final ImmutableSet<Integer> COLUMN_SPACE = ImmutableSet.of(1, 2);

  private static final SparseImmutableTable<Character, Integer, String> SPARSE =
      new SparseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  private static final DenseImmutableTable<Character, Integer, String> DENSE =

     * the associated element if the associated count is one, and otherwise the associated element
     * followed by the characters " x " (space, x and space) followed by the count. Elements and
     * counts are converted to strings as by {@code String.valueOf}.
     */
    @Override
    public String toString() {
      String text = String.valueOf(getElement());

 *   <li><a target="_parent" href="http://www.cymru.com/Bogons/v6bogon.html">http://www.cymru.com/
 *       Bogons/v6bogon.html</a>
 *   <li><a target="_parent" href="http://www.space.net/~gert/RIPE/ipv6-filters.html">http://www.
 *       space.net/~gert/RIPE/ipv6-filters.html</a>
 * </ul>
 *
 * @author Erik Kline
 * @since 5.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault

   *
   * <p>This {@code Collector} uses O(k) memory and takes expected time O(n) (worst-case O(n log
   * k)), as opposed to e.g. {@code Stream.sorted(comparator).limit(k)}, which currently takes O(n
   * log n) time and O(n) space.
   *
   * @throws IllegalArgumentException if {@code k < 0}
   * @since 22.0
   */
  public static <T extends @Nullable Object> Collector<T, ?, List<T>> least(
      int k, Comparator<? super T> comparator) {

  }

  /**
   * Returns {@code n!}, that is, the product of the first {@code n} positive integers, or {@code 1}
   * if {@code n == 0}.
   *
   * <p><b>Warning:</b> the result takes <i>O(n log n)</i> space, so use cautiously.
   *
   * <p>This uses an efficient binary recursive algorithm to compute the factorial with balanced
   * multiplies. It also removes all the 2s from the intermediate products (shifting them back in at

   * This is not the same definition used by other Java APIs. (See a <a
   * href="https://goo.gl/Y6SLWx">comparison of several definitions of "whitespace"</a>.)
   *
   * <p>All Unicode White_Space characters are on the BMP and thus supported by this API.
   *
   * <p><b>Note:</b> as the Unicode definition evolves, we will modify this matcher to keep it up to
   * date.
   *

    if (elements instanceof ImmutableCollection) {
      /*
       * TODO: When given an ImmutableList that's a sublist, copy the referenced
       * portion of the array into a new array to save space?
       */
      @SuppressWarnings("unchecked") // all supported methods are covariant
      ImmutableCollection<E> list = (ImmutableCollection<E>) elements;
      return list.asList();
    }

  }

  /** Creates a new {@link Closer}. */
  public static Closer create() {
    return new Closer(SUPPRESSOR);
  }

  @VisibleForTesting final Suppressor suppressor;

  // only need space for 2 elements in most cases, so try to use the smallest array possible
  private final Deque<Closeable> stack = new ArrayDeque<>(4);
  @CheckForNull private Throwable thrown;

  @VisibleForTesting