def test_cleanUpOnetimeEventObserver(self):

        d = EventDispatcher()
        cb = CallbackTracker()

        d.addOnetimeObserver('//event/test', cb.call)
        d.dispatch(None, '//event/test')
        self.assertEqual(1, cb.called)
        self.assertEqual(0, len(d._eventObservers.pop(0)))
Validate the prerequisites required to use the Amazon S3 cache backend.
dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/words/test/test_xishutil.py/EventDispatcherTest.test_cleanUpOnetimeEventObserver--crossover with--dataset/ETHPy150Open paylogic/pip-accel/pip_accel/caches/s3.py/S3CacheBackend.check_prerequisites