pickling classes with __slots__

[Alex Neyfakh]

I would greatly appreciate an advice on the following matter that was very 
much discussed circa 2002 but in all this discussion I could not find the 
final answer with a code example.

I have a series of new classes with child-parent relationship and each has 
unique __slots__. They don't have __dict__ . I need to be able to pickle 
and unpickle them. As far as I could understand, I need to provide 
__getstate__  and  __setstate__ methods for each class. Is there a 
universally accepted code for each method? If so, what is it? If there is 
no standard, what works?

TIA

Alex