class ChecksumFileSystem extends FilterFileSystem {

  @Override
  public void setConf(Configuration conf) {
    super.setConf(conf);
    if (conf != null) {
      bytesPerChecksum = conf.getInt(LocalFileSystemConfigKeys.LOCAL_FS_BYTES_PER_CHECKSUM_KEY,
		                     LocalFileSystemConfigKeys.LOCAL_FS_BYTES_PER_CHECKSUM_DEFAULT);
      Preconditions.checkState(bytesPerChecksum > 0,
          "bytes per checksum should be positive but was %s",
          bytesPerChecksum);
    }
  }

  public  ChecksumFileSystem(FileSystem fs);

}