(self, other)
| 266 | return NotImplemented |
| 267 | |
| 268 | def __ror__(self, other): |
| 269 | if isinstance(other, _collections_abc.Mapping): |
| 270 | c = self.__class__() |
| 271 | c.update(other) |
| 272 | c.update(self) |
| 273 | return c |
| 274 | return NotImplemented |
| 275 | |
| 276 | |
| 277 | class KeyedRef(ref): |