* automatic-closing approach described above is safer.
 *
 * @param <V> the type of the value of this step
 * @since 30.0
 */
// TODO(dpb): Consider reusing one CloseableList for the entire pipeline, modulo combinations.
@DoNotMock("Use ClosingFuture.from(Futures.immediate*Future)")
@J2ktIncompatible
@ElementTypesAreNonnullByDefault
// TODO(dpb): GWT compatibility.

      BiMap<K, V> synchronizedBiMap(BiMap<K, V> bimap) {
    return Synchronized.biMap(bimap, null);
  }

  /**
   * Returns an unmodifiable view of the specified bimap. This method allows modules to provide
   * users with "read-only" access to internal bimaps. Query operations on the returned bimap "read
   * through" to the specified bimap, and attempts to modify the returned map, whether direct or via