Process a GNU tar extended sparse header, version 0.0.

def _proc_gnusparse_00(self, next, pax_headers, buf):
        """Process a GNU tar extended sparse header, version 0.0.
        """
        offsets = []
        for match in re.finditer(br"\d+ GNU.sparse.offset=(\d+)\n", buf):
            offsets.append(int(match.group(1)))
        numbytes = []
        for match in re.finditer(br"\d+ GNU.sparse.numbytes=(\d+)\n", buf):
            numbytes.append(int(match.group(1)))
        next.sparse = list(zip(offsets, numbytes))