*
   * @param <InElementT> the element type of the input spliterator
   * @param <OutElementT> the (boxed) element type of the output spliterators
   * @param <OutConsumerT> the specialized consumer type for the primitive output type
   * @param <OutSpliteratorT> the primitive spliterator type associated with {@code OutElementT}
   */
  abstract static class FlatMapSpliteratorOfPrimitive<

 *   <li>{@code java.util.Optional} has the additional methods {@code ifPresent}, {@code filter},
 *       {@code flatMap}, and {@code orElseThrow}.
 *   <li>{@code java.util} offers the primitive-specialized versions {@code OptionalInt}, {@code
 *       OptionalLong} and {@code OptionalDouble}, the use of which is recommended; Guava does not
 *       have these.
 * </ul>
 *

  }

  // Inner Classes

  /**
   * Segments are specialized versions of hash tables. This subclass inherits from ReentrantLock
   * opportunistically, just to simplify some locking and avoid separate construction.
   */
  @SuppressWarnings("serial") // This class is never serialized.
  static class Segment<K, V> extends ReentrantLock {

    /*

      } else {
        return ImmutableSet.of();
      }
    }
  }

  /**
   * Returns a {@code Collector} that accumulates the input elements into a new {@code ImmutableSet}
   * with an implementation specialized for enums. Unlike {@link ImmutableSet#toImmutableSet}, the
   * resulting set will iterate over elements in their enum definition order, not encounter order.
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */

  }

  // Inner Classes

  /**
   * Segments are specialized versions of hash tables. This subclass inherits from ReentrantLock
   * opportunistically, just to simplify some locking and avoid separate construction.
   */
  @SuppressWarnings("serial") // This class is never serialized.
  static class Segment<K, V> extends ReentrantLock {

    /*

 *       parallelizing stream operations.
 *   <li>{@code FluentIterable} contains several features not available on {@code Stream}, which are
 *       noted in the method descriptions below.
 *   <li>Streams include primitive-specialized variants such as {@code IntStream}, the use of which
 *       is strongly recommended.
 *   <li>Streams are standard Java, not requiring a third-party dependency.
 * </ul>
 *
 * <h3>Example</h3>
 *

 *       parallelizing stream operations.
 *   <li>{@code FluentIterable} contains several features not available on {@code Stream}, which are
 *       noted in the method descriptions below.
 *   <li>Streams include primitive-specialized variants such as {@code IntStream}, the use of which
 *       is strongly recommended.
 *   <li>Streams are standard Java, not requiring a third-party dependency (but do render your code

      if (collection.size() <= 2L * k) {
        // In this case, just dumping the collection to an array and sorting is
        // faster than using the implementation for Iterator, which is
        // specialized for k much smaller than n.

        @SuppressWarnings("unchecked") // c only contains E's and doesn't escape
        E[] array = (E[]) collection.toArray();
        Arrays.sort(array, this);

import com.google.common.collect.ImmutableMap;
import java.util.Deque;

/** Parser for a map of reversed domain names stored as a serialized radix tree. */
@GwtCompatible
final class TrieParser {

  private static final Joiner DIRECT_JOINER = Joiner.on("");

  /**
   * Parses a serialized trie representation of a map of reversed public suffixes into an immutable

final class SingletonImmutableSet<E> extends ImmutableSet<E> {

  // This reference is used both by the custom field serializer, and by the
  // GWT compiler to infer the elements of the lists that needs to be
  // serialized.
  //
  // Although this reference is non-final, it doesn't change after set creation.
  E element;

  SingletonImmutableSet(E element) {
    this.element = checkNotNull(element);
  }

  @Override