* <p>{@code value} may be null only for a loading reference.
     */
    ValueReference<K, V> copyFor(
        ReferenceQueue<V> queue, @CheckForNull V value, ReferenceEntry<K, V> entry);

    /**
     * Notify pending loads that a new value was set. This is only relevant to loading value
     * references.
     */
    void notifyNewValue(@CheckForNull V newValue);

    /**

  }

  /**
   * Returns an unmodifiable view of the specified set of entries. The {@link Entry#setValue}
   * operation throws an {@link UnsupportedOperationException}, as do any operations that would
   * modify the returned set.
   *
   * @param entrySet the entries for which to return an unmodifiable view
   * @return an unmodifiable view of the entries
   */

  }

  /**
   * Returns an unmodifiable view of the specified set of entries. The {@link Entry#setValue}
   * operation throws an {@link UnsupportedOperationException}, as do any operations that would
   * modify the returned set.
   *
   * @param entrySet the entries for which to return an unmodifiable view
   * @return an unmodifiable view of the entries
   */

     * <p>{@code value} may be null only for a loading reference.
     */
    ValueReference<K, V> copyFor(
        ReferenceQueue<V> queue, @CheckForNull V value, ReferenceEntry<K, V> entry);

    /**
     * Notify pending loads that a new value was set. This is only relevant to loading value
     * references.
     */
    void notifyNewValue(@CheckForNull V newValue);

    /**