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Changes between Initial Version and Version 1 of Ticket #4102, comment 80

initial	v1
10	10
11	11	And still one more thing: the update_fields is passed to the signal handler but its type is not known. If it happens to be a list (or any other mutable container), the signal handler can modify it in place. There is no safety checks for modifications done there. I am not sure if signal handlers being able to modify the list is useful or not, but at least the passed in type should be consistent: either a list or a tuple (actually, set or immutable set could make more sense).
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	13	EDIT: Just noted that there is .delete() calls in the end of the test methods: no need for that, Django's TestCase will do the cleanup for you.