* @author Isaac Shum
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
public final class Maps {
  private Maps() {}

  static <K extends @Nullable Object, V extends @Nullable Object> Iterator<K> keyIterator(
      Iterator<Entry<K, V>> entryIterator) {
    return new TransformedIterator<Entry<K, V>, K>(entryIterator) {
      @Override
      @ParametricNullness
      K transform(Entry<K, V> entry) {

 * @author Isaac Shum
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
public final class Maps {
  private Maps() {}

  static <K extends @Nullable Object, V extends @Nullable Object> Iterator<K> keyIterator(
      Iterator<Entry<K, V>> entryIterator) {
    return new TransformedIterator<Entry<K, V>, K>(entryIterator) {
      @Override
      @ParametricNullness
      K transform(Entry<K, V> entry) {

    @Override
    public void remove() {
      checkState(lastReturned != null);
      LocalCache.this.remove(lastReturned.getKey());
      lastReturned = null;
    }
  }

  final class KeyIterator extends HashIterator<K> {

    @Override
    public K next() {
      return nextEntry().getKey();
    }
  }

  final class ValueIterator extends HashIterator<V> {

    @Override