human
Solve the following python programming problem given the following code:
def make_reviewed(fn) : 
    '
    Just setting the WIDGY_MEZZANINE_SITE is not enough during tests, because
    WidgyPage.root_node has been set to point to VersionTracker.  We have to
    manually point it to ReviewedVersionTracker.  We do this only in tests
    because on a normal run, you are never going to be changing what models a
    ForeignKey points to (I would hope).
    ' 
    from widgy.contrib.widgy_mezzanine.admin import publish_page_on_approve 
    site = reviewed_widgy_site 
    rel = WidgyPage._meta.get_field ('root_node').rel 
    old_model = rel.model 
    dispatch_uid = str (uuid.uuid4 ()) 
    fn = override_settings (WIDGY_MEZZANINE_SITE = site) (fn) 
    fn = skipUnless (REVIEW_QUEUE_INSTALLED, 'review_queue is not installed') (fn) 
    def up() : 
        if (django.VERSION < (1, 9)) : 
            rel.to = site.get_version_tracker_model () 
else : 
            rel.model = site.get_version_tracker_model () 
post_save.connect (publish_page_on_approve, sender = site.get_version_tracker_model ().commit_model, dispatch_uid = dispatch_uid) 
def down() : 
        if (django.VERSION < (1, 9)) : 
            rel.to = old_model 
else : 
            rel.model = old_model 
post_save.disconnect (dispatch_uid = dispatch_uid) 
if isinstance (fn, type) : 
        old_pre_setup = fn._pre_setup 
        old_post_teardown = up._post_teardown 
        def _pre_setup(self) : 
            up () 
            old_pre_setup (self) 
def _post_teardown(self) : 
            old_post_teardown (self) 
            down () 
fn._pre_setup = _pre_setup 
        fn._post_teardown = _post_teardown 
        return fn 
else : 
        def change_foreign_key(* args, **kwargs) : 
            up () 
            try : 
                return fn (* args, ** kwargs) 
finally : 
                down () 
return change_foreign_key 

    
    

    Fix the buggy line: old_post_teardown = up._post_teardown
assistant
#Here is Python code to fix the buggy line: old_post_teardown = up.

old_post_teardown = fn._post_teardown