}

  // enum singleton pattern
  private enum ToStringFunction implements Function<Object, String> {
    INSTANCE;

    @Override
    public String apply(Object o) {
      checkNotNull(o); // eager for GWT.
      return o.toString();
    }

    @Override
    public String toString() {
      return "Functions.toStringFunction()";
    }
  }

  /**
   * Returns the identity function.
   *

import java.util.SortedSet;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Derived suite generators, split out of the suite builders so that they are available to GWT.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@NullMarked
public final class DerivedCollectionGenerators {
  public static class MapEntrySetGenerator<K extends @Nullable Object, V extends @Nullable Object>

   *     greater than {@code b}; or zero if they are equal
   */
  @SuppressWarnings("InlineMeInliner") // Integer.compare unavailable under GWT+J2CL
  public static int compare(int a, int b) {
    return Ints.compare(flip(a), flip(b));
  }

  /**
   * Returns the value of the given {@code int} as a {@code long}, when treated as unsigned.
   *

          return super.setValue(checkNotNull(value));
        }

        @Override
        public boolean equals(@Nullable Object object) {
          // TODO(lowasser): identify why this affects GWT tests
          return standardEquals(object);
        }
      };
    }
  }

  /**
   * {@inheritDoc}
   *
   * <p>The returned map's views have iterators that don't support {@code remove()}.

    // It would be nice to be able to return a real concurrent
    // collection like ConcurrentLinkedQueue, so that e.g. concurrent
    // iteration would work, but that would not be GWT-compatible.
    // We are not "just" inheriting from ArrayList here as this doesn't work for J2kt.
    return new AbstractList<T>() {
      final ArrayList<T> data = new ArrayList<>();

      @Override

  private static final int ODD_POWERS_OF_TWO = 0xaaaaaaaa;

  @VisibleForTesting
  static boolean isEvenLevel(int index) {
    int oneBased = ~~(index + 1); // for GWT
    checkState(oneBased > 0, "negative index");
    return (oneBased & EVEN_POWERS_OF_TWO) > (oneBased & ODD_POWERS_OF_TWO);
  }

  /**

   * @since 11.0
   */
  public static <E extends @Nullable Object> SortedMultiset<E> unmodifiableSortedMultiset(
      SortedMultiset<E> sortedMultiset) {
    // it's in its own file so it can be emulated for GWT
    return new UnmodifiableSortedMultiset<>(checkNotNull(sortedMultiset));
  }

  /**
   * Returns an immutable multiset entry with the specified element and count. The entry will be
   * serializable if {@code e} is.

 * to prioritize memory over CPU.
 *
 * @author Louis Wasserman
 * @author Jon Noack
 */
@GwtIncompatible // not worth using in GWT for now
class CompactHashMap<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMap<K, V> implements Serializable {
  /*

   * @since 11.0
   */
  public static <E extends @Nullable Object> SortedMultiset<E> unmodifiableSortedMultiset(
      SortedMultiset<E> sortedMultiset) {
    // it's in its own file so it can be emulated for GWT
    return new UnmodifiableSortedMultiset<>(checkNotNull(sortedMultiset));
  }

  /**
   * Returns an immutable multiset entry with the specified element and count. The entry will be
   * serializable if {@code e} is.

 * @author Louis Wasserman
 * @since 12.0
 */
@GwtIncompatible // hasn't been tested yet
public abstract class ImmutableSortedMultiset<E> extends ImmutableMultiset<E>
    implements SortedMultiset<E> {
  // TODO(lowasser): GWT compatibility

  /**
   * Returns a {@code Collector} that accumulates the input elements into a new {@code
   * ImmutableMultiset}. Elements are sorted by the specified comparator.
   *