def tearDown(self):
        state.reset_instance()
L{MemCacheProtocol.delete} returns a L{Deferred} which is called back
dataset/ETHPy150Open duerrp/pyexperiment/tests/test_persistent_memoize.py/TestPersistentMemoize.tearDown--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/test/test_memcache.py/CommandMixin.test_delete