def test_noReference(self):
        test = self.__class__('test_successful')
        ref = weakref.ref(test)
        test.run(self.result)
        self.assertSuccessful(test, self.result)
        del test
        gc.collect()
        self.assertIdentical(ref(), None)
Returns the SQL command that drops a foreign key.
dataset/ETHPy150Open nlloyd/SubliminalCollaborator/libs/twisted/trial/test/test_tests.py/SuccessMixin.test_noReference--crossover with--dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/Django-1.6.10/django/db/backends/__init__.py/BaseDatabaseOperations.drop_foreignkey_sql