def __getstate__(self, dict=None):
        """Get state, adding a version number to it on its way out.
        """
        dct = copy.copy(dict or self.__dict__)
        bases = _aybabtu(self.__class__)
        bases.reverse()
        bases.append(self.__class__) # don't forget me!!
        for base in bases:
            if 'persistenceForgets' in base.__dict__:
                for slot in base.persistenceForgets:
                    if slot in dct:
                        del dct[slot]
            if 'persistenceVersion' in base.__dict__:
                dct['%s.persistenceVersion' % reflect.qual(base)] = base.persistenceVersion
        return dct
Get state, adding a version number to it on its way out.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/persisted/styles.py