import com.google.common.annotations.GwtCompatible;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/**
 * Provides static methods for working with {@link Comparator} instances. For many other helpful
 * comparator utilities, see either {@code Comparator} itself (for Java 8+), or {@code

    };
  }

  @Override
  public @Nullable Entry<K, V> firstEntry() {
    return delegate.firstEntry();
  }

  @Override
  public K firstKey() {
    return delegate.firstKey();
  }

  @Override
  public @Nullable Entry<K, V> floorEntry(K key) {
    return delegate.floorEntry(checkValid(key));
  }

  @Override
  public @Nullable K floorKey(K key) {

import java.util.concurrent.ConcurrentHashMap;
import org.jspecify.annotations.Nullable;

/**
 * Methods factored out so that they can be emulated differently in GWT.
 *
 * @author Hayward Chan
 */
@GwtCompatible
final class Platform {

  /** Returns the platform preferred implementation of a map based on a hash table. */
  static <K extends @Nullable Object, V extends @Nullable Object>
      Map<K, V> newHashMapWithExpectedSize(int expectedSize) {

    int nextSegmentIndex;
    int nextTableIndex;
    @Nullable Segment<K, V> currentSegment;
    @Nullable AtomicReferenceArray<ReferenceEntry<K, V>> currentTable;
    @Nullable ReferenceEntry<K, V> nextEntry;
    @Nullable WriteThroughEntry nextExternal;
    @Nullable WriteThroughEntry lastReturned;

    HashIterator() {
      nextSegmentIndex = segments.length - 1;

    }

    @Override
    Map<R, @Nullable V> getValue(int index) {
      return new Column(index);
    }

    @Override
    Map<R, @Nullable V> setValue(int index, Map<R, @Nullable V> newValue) {
      throw new UnsupportedOperationException();
    }

    @Override
    public @Nullable Map<R, @Nullable V> put(C key, Map<R, @Nullable V> value) {
      throw new UnsupportedOperationException();

  public VerifyException(@Nullable String message) {
    super(message);
  }

  /**
   * Constructs a {@code VerifyException} with the cause {@code cause} and a message that is {@code
   * null} if {@code cause} is null, and {@code cause.toString()} otherwise.
   *
   * @since 19.0
   */
  public VerifyException(@Nullable Throwable cause) {
    super(cause);
  }

  /**

   * @since 11.0
   */
  public static <R extends @Nullable Object, C extends @Nullable Object, V extends @Nullable Object>
      Table<R, C, V> unmodifiableTable(Table<? extends R, ? extends C, ? extends V> table) {
    return new UnmodifiableTable<>(table);
  }

  private static class UnmodifiableTable<
          R extends @Nullable Object, C extends @Nullable Object, V extends @Nullable Object>

 *
 * @param <B> the common supertype that all values will share. When in doubt, just use {@link
 *     Object}, or use {@code @Nullable Object} to allow null values.
 * @since 2.0
 */
@DoNotMock("Use ImmutableClassToInstanceMap or MutableClassToInstanceMap")
@GwtCompatible
public interface ClassToInstanceMap<B extends @Nullable Object>
    extends Map<Class<? extends @NonNull B>, B> {
  /**

   */
  static <T extends @Nullable Object> T[] toArrayImpl(
      @Nullable Object[] src, int offset, int len, T[] dst) {
    checkPositionIndexes(offset, offset + len, src.length);
    if (dst.length < len) {
      dst = newArray(dst, len);
    } else if (dst.length > len) {
      @Nullable Object[] unsoundlyCovariantArray = dst;
      unsoundlyCovariantArray[len] = null;
    }

 * @author Louis Wasserman
 */
@GwtCompatible
abstract class AbstractMultiset<E extends @Nullable Object> extends AbstractCollection<E>
    implements Multiset<E> {
  // Query Operations

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

  @Override
  public boolean contains(@Nullable Object element) {
    return count(element) > 0;
  }

  // Modification Operations