}
    }
  }

  /** Base class for {@link InternalEntry} implementations for weak keys. */
  abstract static class AbstractWeakKeyEntry<K, V, E extends InternalEntry<K, V, E>>
      extends WeakReference<K> implements InternalEntry<K, V, E> {
    final int hash;

    AbstractWeakKeyEntry(ReferenceQueue<K> queue, K key, int hash) {
      super(key, queue);
      this.hash = hash;
    }

    @Override