}
          },
          executor);
    }
  }

  @Override
  public String toString() {
    return state.closingFutureToString();
  }

  private static void closeQuietly(@Nullable AutoCloseable closeable, Executor executor) {
    if (closeable == null) {
      return;
    }
    try {
      executor.execute(
          () -> {
            try {