* than all other values, and orders the rest using {@code valueComparator} on the contained
   * value.
   *
   * @since 22.0 (but only since 33.4.0 in the Android flavor)
   */
  public static <T> Comparator<Optional<T>> emptiesFirst(Comparator<? super T> valueComparator) {
    checkNotNull(valueComparator);
    return Comparator.<Optional<T>, @Nullable T>comparing(

  }

  /**
   * Schedules {@code callable} on the specified {@code executor}, returning a {@code Future}.
   *
   * @throws RejectedExecutionException if the task cannot be scheduled for execution
   * @since 33.4.0 (but since 28.0 in the JRE flavor)
   */
  @J2ktIncompatible
  @GwtIncompatible // java.util.concurrent.ScheduledExecutorService
  @IgnoreJRERequirement // Users will use this only if they're already using Duration.

   *   lines.map(...)
   *      .filter(...)
   *      .forEach(...);
   * }
   * }
   *
   * @throws IOException if an I/O error occurs while opening the stream
   * @since 33.4.0 (but since 22.0 in the JRE flavor)
   */
  @MustBeClosed
  // If users use this when they shouldn't, we hope that NewApi will catch subsequent Stream calls.
  @IgnoreJRERequirement

   *   lines.map(...)
   *      .filter(...)
   *      .forEach(...);
   * }
   * }
   *
   * @throws IOException if an I/O error occurs while opening the stream
   * @since 22.0 (but only since 33.4.0 in the Android flavor)
   */
  @MustBeClosed
  public Stream<String> lines() throws IOException {
    BufferedReader reader = openBufferedStream();

 * ListeningExecutorService.submit} on a service obtained from {@link
 * MoreExecutors#listeningDecorator}.
 *
 * @author Sven Mawson
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public class ListenableFutureTask<V extends @Nullable Object> extends FutureTask<V>
    implements ListenableFuture<V> {

 * See for example <a
 * href="http://gee.cs.oswego.edu/dl/jsr166/dist/docs/java.base/java/util/concurrent/atomic/DoubleAdder.html">
 * DoubleAdder</a>.
 *
 * @author Doug Lea
 * @author Martin Buchholz
 * @since 11.0
 */
@GwtIncompatible
@J2ktIncompatible
@ReflectionSupport(value = ReflectionSupport.Level.FULL)
public class AtomicDouble extends Number {
  private static final long serialVersionUID = 0L;

   * hasNext()} returns {@code false}, whichever comes first.
   *
   * @return the number of elements the iterator was advanced
   * @since 13.0 (since 3.0 as {@code Iterators.skip})
   */
  @CanIgnoreReturnValue
  public static int advance(Iterator<?> iterator, int numberToAdvance) {
    checkNotNull(iterator);

   * writeLines(lines, System.getProperty("line.separator"))}.
   *
   * @throws IOException if an I/O error occurs while writing to this sink
   * @since 33.4.0 (but since 22.0 in the JRE flavor)
   */
  @IgnoreJRERequirement // Users will use this only if they're already using Stream.
  public void writeLines(Stream<? extends CharSequence> lines) throws IOException {

      return this;
    }

    /**
     * {@inheritDoc}
     *
     * @since 11.0
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<K, V> put(Entry<? extends K, ? extends V> entry) {
      super.put(entry);
      return this;
    }

    /**
     * {@inheritDoc}
     *
     * @since 19.0
     */
    @CanIgnoreReturnValue
    @Override

   *
   * @since 15.0
   */
  public static HashFunction sipHash24() {
    return SipHashFunction.SIP_HASH_24;
  }

  /**
   * Returns a hash function implementing the <a href="https://131002.net/siphash/">64-bit
   * SipHash-2-4 algorithm</a> using the given seed.
   *
   * @since 15.0
   */
  public static HashFunction sipHash24(long k0, long k1) {