. anyobject argument
      Stack after:  ... anyobject

      where anyobject may have been mutated, as follows:

      If the object has a __setstate__ method,

          anyobject.__setstate__(argument)

      is called.

      Else the argument must be a dict, the object must have a __dict__, and
      the object is updated via

          anyobject.__dict__.update(argument)
      