*   Update `tf.keras` to the Keras 2.1.6 API.
*   Added
    [`tf.keras.layers.CuDNNGRU`](https://www.tensorflow.org/versions/r1.9/api_docs/python/tf/keras/layers/CuDNNGRU)
    and
    [`tf.keras.layers.CuDNNLSTM`](https://www.tensorflow.org/versions/r1.9/api_docs/python/tf/keras/layers/CuDNNLSTM)
    layers.

func (fi *FileInfo) TierFreeVersionID() string {
	return fi.Metadata[ReservedMetadataPrefixLower+tierFVID]
}

// SetTierFreeVersion sets fi as a free-version. This method is used by
// lower layers to indicate a free-version.
func (fi *FileInfo) SetTierFreeVersion() {
	if fi.Metadata == nil {
		fi.Metadata = make(map[string]string)
	}
	fi.Metadata[ReservedMetadataPrefixLower+tierFVMarker] = ""
}

   * @throws NullPointerException if any of {@code elements} is null
   * @since 7.0 (source-compatible since 2.0)
   */
  // This the best we could do to get copyOfEnumSet to compile in the mainline.
  // The suppression also covers the cast to E[], discussed below.
  // In the backport, we don't have those cases and thus don't need this suppression.
  // We keep it to minimize diffs.
  @SuppressWarnings("unchecked")

   */
  @J2ktIncompatible // serialization
  static class SerializedForm<K, V> implements Serializable {
    // This object retains references to collections returned by keySet() and value(). This saves
    // bytes when the both the map and its keySet or value collection are written to the same
    // instance of ObjectOutputStream.

		// ignore if user is already deleted.
		err = nil
	}
	delete(cache.iamUsersMap, accessKey)

	cache.updatedAt = time.Now()

	return err
}

// SetTempUser - saves temporary (STS) credential to storage and cache. If a
// policy name is given, it is associated with the parent user specified in the
// credential.

			markDelete = false
		}
		if opts.VersionPurgeStatus() == Complete {
			markDelete = false
		}
		// now, since VersionPurgeStatus() is already set, we can let the
		// lower layers decide this. This fixes a regression that was introduced
		// in PR #14555 where !VersionPurgeStatus.Empty() is automatically
		// considered as Delete marker true to avoid listing such objects by