@Override public void finish() throws IOException {
  super.finish();
  writeLong(crc.getValue());
  writeLong(crc.tbytes);
}

@ Override public void finish ( ) throws IOException { super . finish ( ) ; writeLong ( crc . getValue ( ) ) ; writeLong ( crc . tbytes ) ; }
indicates to the stream that all data has been written out , and any gzip terminal data can now be written .
