* @param closingExecutor the object will be closed on this executor
     * @return the first argument
     */
    @CanIgnoreReturnValue
    @ParametricNullness
    // TODO(b/163345357): Widen bound to AutoCloseable once we require API Level 19.
    public <C extends @Nullable Object & @Nullable Closeable> C eventuallyClose(
        @ParametricNullness C closeable, Executor closingExecutor) {