@transaction.atomic
def save_model(self, request, obj, form, change):
    rv = super().save_model(request, obj, form, change)
    obj.change_trigger(form.changed_data)
    return rv
@transaction.atomic
def save_model(self, request, obj, form, change):
    rv = super().save_model(request, obj, form, change)
    obj.change_trigger(form.changed_data)
    return rv