import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * A skeleton {@code Multimap} implementation, not necessarily in terms of a {@code Map}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
abstract class AbstractMultimap<K extends @Nullable Object, V extends @Nullable Object>
    implements Multimap<K, V> {
  @Override
  public boolean isEmpty() {

    return result;
  }

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

  @Override
  public @Nullable Entry<E> lastEntry() {
    return delegate().lastEntry();
  }

  @Override
  public @Nullable Entry<E> pollFirstEntry() {
    throw new UnsupportedOperationException();
  }

  @Override
  public @Nullable Entry<E> pollLastEntry() {

import org.jspecify.annotations.Nullable;

/**
 * Derived suite generators for Guava collection interfaces, split out of the suite builders so that
 * they are available to GWT.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public final class DerivedGoogleCollectionGenerators {
  public static class MapGenerator<K extends @Nullable Object, V extends @Nullable Object>

    static final Listener TOMBSTONE = new Listener();
    // null only for TOMBSTONE
    final @Nullable Runnable task;
    // null only for TOMBSTONE
    final @Nullable Executor executor;

    // writes to next are made visible by subsequent CAS's on the listeners field
    @Nullable Listener next;

    Listener(Runnable task, Executor executor) {
      this.task = task;
      this.executor = executor;

abstract class AbstractAbstractFutureTest extends TestCase {
  @SuppressWarnings("initialization.field.uninitialized")
  private TestedFuture<@Nullable Integer> future;

  @SuppressWarnings("initialization.field.uninitialized")
  private AbstractFuture<@Nullable Integer> delegate;

  abstract AbstractFuture<@Nullable Integer> newDelegate();

  @Override
  protected void setUp() {
    future = TestedFuture.create();
    delegate = newDelegate();
  }

    };
  }

  @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) {

      assertTrue(Thread.holdsLock(mutex));
      return delegate.containsRow(rowKey);
    }

    @Override
    public @Nullable V get(Object rowKey, Object columnKey) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.get(rowKey, columnKey);
    }

    @Override
    public @Nullable V put(R rowKey, C columnKey, V value) {
      assertTrue(Thread.holdsLock(mutex));

  @Override
  public <T extends @NonNull B> @Nullable T getInstance(Class<T> type) {
    return trustedGet(TypeToken.of(type));
  }

  @Override
  public <T extends @NonNull B> @Nullable T getInstance(TypeToken<T> type) {
    return trustedGet(type.rejectTypeVariables());
  }

  @Override
  @CanIgnoreReturnValue
  public <T extends B> @Nullable T putInstance(

  }

  private static Iterable<@Nullable Object> iterable(
      @Nullable Object first, @Nullable Object second, @Nullable Object[] rest) {
    checkNotNull(rest);
    return new AbstractList<@Nullable Object>() {
      @Override
      public int size() {
        return rest.length + 2;
      }

      @Override
      public @Nullable Object get(int index) {
        switch (index) {

   *
   * @since 23.1 (varargs overload since 17.0)
   */
  public static void verify(
      boolean expression,
      String errorMessageTemplate,
      @Nullable Object p1,
      @Nullable Object p2,
      @Nullable Object p3,
      @Nullable Object p4) {
    if (!expression) {
      throw new VerifyException(lenientFormat(errorMessageTemplate, p1, p2, p3, p4));
    }
  }

  /*