checkNotNull(file);
    checkNotNull(mode);

    Closer closer = Closer.create();
    try {
      RandomAccessFile raf =
          closer.register(new RandomAccessFile(file, mode == MapMode.READ_ONLY ? "r" : "rw"));
      FileChannel channel = closer.register(raf.getChannel());
      return channel.map(mode, 0, size == -1 ? channel.size() : size);
    } catch (Throwable e) {
      throw closer.rethrow(e);