| >>> from mechanize._http import MechanizeRobotFileParser | |
| Calling .set_opener() without args sets a default opener. | |
| >>> rfp = MechanizeRobotFileParser() | |
| >>> rfp.set_opener() | |
| >>> rfp._opener # doctest: +ELLIPSIS | |
| <mechanize._opener.OpenerDirector instance at ...> |