return delegateList().equals(obj);
  }

  @Override
  public int hashCode() {
    return delegateList().hashCode();
  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    return Iterators.unmodifiableIterator(delegateList().iterator());
  }

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && delegateList().contains(object);
  }

  @Override

  private abstract class Itr<T extends @Nullable Object> implements Iterator<T> {
    final Iterator<Entry<K, Collection<V>>> keyIterator;
    @Nullable K key;
    @Nullable Collection<V> collection;
    Iterator<V> valueIterator;

    Itr() {
      keyIterator = map.entrySet().iterator();
      key = null;
      collection = null;
      valueIterator = Iterators.emptyModifiableIterator();
    }

          return standardToArray(array);
        }
      };
    }

    private static <K, V extends @Nullable Object> Iterator<Entry<K, V>> transformEntries(
        Iterator<Entry<K, V>> entries) {
      return Iterators.transform(entries, UnmodifiableEntry::new);
    }

    private UnmodifiableEntry(Entry<K, V> delegate) {
      this.delegate = checkNotNull(delegate);
    }

 * PeekingIterator}</a>.
 *
 * @author Mick Killianey
 * @since 2.0
 */
@DoNotMock("Use Iterators.peekingIterator")
@GwtCompatible
public interface PeekingIterator<E extends @Nullable Object> extends Iterator<E> {
  /**
   * Returns the next element in the iteration, without advancing the iteration.
   *
   * <p>Calls to {@code peek()} should not change the state of the iteration, except that it

        @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();
        }
      };

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;
import java.util.Iterator;

/**
 * Creates iterators to be tested.
 *
 * @param <E> the element type of the iterator.
 * @author George van den Driessche
 */
@GwtCompatible
public interface TestIteratorGenerator<E> {
  Iterator<E> get();

   * endpoints of a directed edge).
   */
  public abstract boolean isOrdered();

  /** Iterates in the order {@link #nodeU()}, {@link #nodeV()}. */
  @Override
  public final UnmodifiableIterator<N> iterator() {
    return Iterators.forArray(nodeU, nodeV);
  }

  /**
   * Two ordered {@link EndpointPair}s are equal if their {@link #source()} and {@link #target()}

import java.util.Collections;
import java.util.Iterator;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A utility for testing an Iterator implementation by comparing its behavior to that of a "known
 * good" reference implementation. In order to accomplish this, it's important to test a great
 * variety of sequences of the {@link Iterator#next}, {@link Iterator#hasNext} and {@link

package com.google.common.collect.testing;

import com.google.common.annotations.GwtCompatible;
import java.util.Iterator;

/**
 * Creates iterators to be tested.
 *
 * @param <E> the element type of the iterator.
 * @author George van den Driessche
 */
@GwtCompatible
public interface TestIteratorGenerator<E> {
  Iterator<E> get();

  }

  @Override
  Iterator<Cell<R, C, V>> cellIterator() {
    return new CellIterator();
  }

  private final class CellIterator implements Iterator<Cell<R, C, V>> {
    final Iterator<Entry<R, Map<C, V>>> rowIterator = backingMap.entrySet().iterator();
    @Nullable Entry<R, Map<C, V>> rowEntry;
    Iterator<Entry<C, V>> columnIterator = Iterators.emptyModifiableIterator();

    @Override