docs: public static long getChecksum(final File file, final boolean crc)
  		throws FileNotFoundException, IOException
  	{
  		try (CheckedInputStream cis = crc
  			? new CheckedInputStream(new FileInputStream(file), new CRC32())
  			: new CheckedInputStream(new FileInputStream(file), new Adler32());)
  		{
  			final int length = (int)file.length();
  			final byte[] buffer = new byte[length];
  			long checksum = 0;
  			while (cis.read(buffer) >= 0)
  			{
  				checksum = cis.getChecksum().getValue();
  			}
  			checksum = cis.getChecksum().getValue();
  			return checksum;
  		}
  	}