def drop_rel(self, rId):
        if self._rel_ref_count(rId) < 2:
            del self.rels[rId]
alternate: django-admin builtin commands succeed if settings are provided in the environment
dataset/ETHPy150Open python-openxml/python-docx/docx/opc/part.py/Part.drop_rel--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/tests/regressiontests/admin_scripts/tests.py/DjangoAdminAlternateSettings.test_builtin_with_environment