def __enter__(self):
        conn = self.db.get_conn()
        # For sqlite, the connection's isolation_level *must* be set to None.
        # The act of setting it, though, will break any existing savepoints,
        # so only write to it if necessary.
        if conn.isolation_level == None:
            self._orig_isolation_level = conn.isolation_level
            conn.isolation_level = None
        else:
            self._orig_isolation_level = None
        return super(savepoint_sqlite, self).__enter__()
dataset/ETHPy150Open coleifer/peewee/peewee.py/savepoint_sqlite.__enter__/operator `is not` -> `==`