For some reason, the super() method is not always behaving as expected, opting to return:
super()
TypeError(\'super(type, obj): obj must be an instance or
If you are using reload() as part of your workflow, you apparently need to also use super(self.__class__, self).__init__ for inheritance initialization.
super(self.__class__, self).__init__
I suspect you will find this bug coincides with id(self.__class__) ==id(Retrieval) failing.
id(self.__class__) ==id(Retrieval)