def test_deferredResult(self):
        d = threads.deferToThread(lambda x, y=5: x + y, 3, y=4)
        d.addCallback(self.assertEqual, 7)
        return d
L{threads.deferToThread} executes the function passed, and correctly
dataset/ETHPy150Open twisted/twisted/twisted/test/test_threads.py/DeferredResultTests.test_deferredResult