final Queue<RemovalNotification<K, V>> removalNotificationQueue;

  /**
   * A listener that is invoked when an entry is removed due to expiration or garbage collection of
   * soft/weak entries.
   */
  final RemovalListener<K, V> removalListener;

  /** Measures time in a testable way. */
  final Ticker ticker;

      }
    };

    abstract Equivalence<Object> defaultEquivalence();
  }

  /**
   * Implementation for the EntryIterator, which is used to build Key and Value iterators.
   *
   * <p>Expiration is only checked on hasNext(), so as to ensure that a next() call never returns
   * null when hasNext() has already been called.
   */
  class EntryIterator implements Iterator<Entry<K, V>> {

  final Queue<RemovalNotification<K, V>> removalNotificationQueue;

  /**
   * A listener that is invoked when an entry is removed due to expiration or garbage collection of
   * soft/weak entries.
   */
  final RemovalListener<K, V> removalListener;

  /** Measures time in a testable way. */
  final Ticker ticker;