Process a GNU tar extended sparse header, version 0.1.

def _proc_gnusparse_01(self, next, pax_headers):
        """Process a GNU tar extended sparse header, version 0.1.
        """
        sparse = [int(x) for x in pax_headers["GNU.sparse.map"].split(",")]
        next.sparse = list(zip(sparse[::2], sparse[1::2]))