def test_cancelCancelledDelayedCall(self):
        call = reactor.callLater(0, lambda: None)
        call.cancel()
        self.assertRaises(error.AlreadyCancelled, call.cancel)
Test that cancelling a DelayedCall which has already been cancelled
dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/test/test_internet.py/TimeTestCase.test_cancelCancelledDelayedCall