code: def _superdir(self):
          
          attrs = set()
          cls = self.__class__
          if hasattr(cls, '__all_slots__'):
              attrs.update(cls.__all_slots__)
          for bcls in cls.__mro__:
              if hasattr(bcls, '__dict__'):
                  attrs.update(bcls.__dict__)
          return attrs
docs: Return a list of slots and methods, including those from subclasses.