- # assume it's a simple pair (will raise if it's not)
- rg = self._range_type(rg[0], rg[1])
+ if self._range_type._is_type(rg):
+ rg = self._range_type(rg)
+ else:
+ # assume it's a simple pair (will raise if it's not)
+ rg = self._range_type(rg[0], rg[1])