* "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multimap">{@code Multimap}</a>.
 *
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible
public interface ListMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends Multimap<K, V> {
  /**
   * {@inheritDoc}
   *
   * <p>Because the values for a given key may have duplicates and follow the insertion ordering,

 */
@GwtCompatible
public abstract class AbstractSequentialIterator<T> extends UnmodifiableIterator<T> {
  private @Nullable T nextOrNull;

  /**
   * Creates a new iterator with the given first element, or, if {@code firstOrNull} is null,
   * creates a new empty iterator.
   */
  protected AbstractSequentialIterator(@Nullable T firstOrNull) {
    this.nextOrNull = firstOrNull;
  }

  /**

  }

  @CanIgnoreReturnValue // TODO(cpovirk): Consider removing this?
  @Override
  public @Nullable E poll() {
    return delegate().poll();
  }

  @CanIgnoreReturnValue
  @Override
  @ParametricNullness
  public E remove() {
    return delegate().remove();
  }

  @Override
  public @Nullable E peek() {
    return delegate().peek();
  }

  @Override
  @ParametricNullness

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.features.CollectionSize;
import java.util.Collection;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * The subject-generator interface accepted by Collection testers, for testing a Collection at one
 * particular {@link CollectionSize}.
 *

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.api.cache;

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Nullable;

/**
 * Interface defining metadata for cache behavior and lifecycle management.
 * Implementations can specify how long cached data should be retained.
 *
 * @since 4.0.0
 */
@Experimental

// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked
public class ListMultimapAsMapTester<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractListMultimapTester<K, V> {
  public void testAsMapValuesImplementList() {
    for (Collection<V> valueCollection : multimap().asMap().values()) {

// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked
public class ListMultimapAsMapTester<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractListMultimapTester<K, V> {
  public void testAsMapValuesImplementList() {
    for (Collection<V> valueCollection : multimap().asMap().values()) {

 */
@Experimental
@Immutable
@Provider
public interface Node {

    /**
     * @return artifact for this node
     */
    @Nullable
    Artifact getArtifact();

    /**
     * @return dependency for this node
     */
    @Nullable
    Dependency getDependency();

    /**
     * Gets the child nodes of this node.
     *
     * @return the child nodes of this node, never {@code null}
     */

   * as well.
   */
  @Override
  public abstract ImmutableMap<R, Map<C, V>> rowMap();

  @Override
  public boolean contains(@Nullable Object rowKey, @Nullable Object columnKey) {
    return get(rowKey, columnKey) != null;
  }

  @Override
  public boolean containsValue(@Nullable Object value) {
    return values().contains(value);
  }

  /**
   * Guaranteed to throw an exception and leave the table unmodified.

import java.util.Set;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
import java.util.logging.Level;
import org.jspecify.annotations.Nullable;

/**
 * A helper which does some thread-safe operations for aggregate futures, which must be implemented
 * differently in GWT. Namely:
 *
 * <ul>
 *   <li>Lazily initializes a set of seen exceptions