def close(self):
        """
        Closes the cursor. The cursor is unusable from this point.
        """
        conn = self._conn
        if conn is not None:
            conn = conn()
        if conn is not None:
            if self is conn._active_cursor:
                conn._active_cursor = conn._main_cursor
                self._session = None
            self._conn = None
Closes the cursor. The cursor is unusable from this point.