def METHOD_NAME(self):
    """gzip header with extra field"""
    # the file was picked up from boost bug report
    with open(os.path.join(self.test_dir, 'sample.txt.gz'), "rb") as f:
        gzipped = f.read()
    self.assertEqual(zlib.decompress(gzipped, zlib.MAX_WBITS | 16), b'hello there\n')