class GoogleCloudStorageGrpcReadChannel implements SeekableByteChannel {

  @Override
  public long size() throws IOException {
    if (!isOpen()) {
      throw new ClosedChannelException();
    }

    return objectSize;
  }

  private  GoogleCloudStorageGrpcReadChannel(
      StorageBlockingStub gcsGrpcBlockingStub,
      String bucketName,
      String objectName,
      long objectGeneration,
      long objectSize,
      GoogleCloudStorageReadOptions readOptions);

}