def _substitute(self, old_instance):
        self.pk = old_instance.pk
The postrelease_after hook is by far the trickiest part of this releaser
dataset/ETHPy150Open ramusus/django-twitter-api/twitter_api/models.py/TwitterModel._substitute--crossover with--dataset/ETHPy150Open spacetelescope/PyFITS/pyfits/_release.py/_test_postrelease_after