* equal to any other equality groups added to this tester.
   *
   * <p>The {@code @Nullable} annotations on the {@code equalityGroup} parameter imply that the
   * objects, and the array itself, can be null. That is for programmer convenience, when the
   * objects come from factory methods that are themselves {@code @Nullable}. In reality neither the
   * array nor its contents can be null, but it is not useful to force the use of {@code

   * not have been inserted consecutively.
   */
  private final @Nullable List<NodeConnection<N>> orderedNodeConnections;

  private int predecessorCount;
  private int successorCount;

  private DirectedGraphConnections(
      Map<N, Object> adjacentNodeValues,
      @Nullable List<NodeConnection<N>> orderedNodeConnections,
      int predecessorCount,
      int successorCount) {

      new IteratorOperation() {
        @Override
        public @Nullable Object execute(Iterator<?> iterator) {
          iterator.remove();
          return null;
        }
      };

  private static final IteratorOperation NEXT_METHOD =
      new IteratorOperation() {
        @Override
        public @Nullable Object execute(Iterator<?> iterator) {
          return iterator.next();
        }

  }

  @Override
  public @Nullable T orNull() {
    return null;
  }

  @Override
  public Set<T> asSet() {
    return Collections.emptySet();
  }

  @Override
  public <V> Optional<V> transform(Function<? super T, V> function) {
    checkNotNull(function);
    return Optional.absent();
  }

  @Override
  public boolean equals(@Nullable Object obj) {
    return this == obj;
  }

 * methods that they depend on are thread-safe.
 *
 * @author Mike Bostock
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
public abstract class ForwardingMapEntry<K extends @Nullable Object, V extends @Nullable Object>
    extends ForwardingObject implements Map.Entry<K, V> {
  // TODO(lowasser): identify places where thread safety is actually lost

  /** Constructor for use by subclasses. */

    return super.toString();
  }

  @Override
  public boolean equals(@Nullable Object o) {
    assertTrue(Thread.holdsLock(mutex));
    return super.equals(o);
  }

  @Override
  public int hashCode() {
    assertTrue(Thread.holdsLock(mutex));
    return super.hashCode();
  }

  @Override
  public boolean add(@Nullable E o) {
    assertTrue(Thread.holdsLock(mutex));
    return super.add(o);
  }

   *
   * 2. `other[size] = null` is unsound. We could "fix" this by requiring callers to pass in an
   * array with a nullable element type. But probably they usually want an array with a non-nullable
   * type. That said, we could *accept* a `@Nullable T[]` (which, given that we treat arrays as
   * covariant, would still permit a plain `T[]`) and return a plain `T[]`. But of course that would

   * 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 org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A generator for {@code ListMultimap} implementations based on test data.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public interface TestListMultimapGenerator<K extends @Nullable Object, V extends @Nullable Object>

import com.google.common.base.Predicate;
import java.util.Map.Entry;
import org.jspecify.annotations.Nullable;

/**
 * An interface for all filtered multimap types.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
interface FilteredMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends Multimap<K, V> {
  Multimap<K, V> unfiltered();

  Predicate<? super Entry<K, V>> entryPredicate();