def test_pausedDeferredChained(self):
        """
        A paused Deferred encountered while pushing a result forward through a
        chain does not prevent earlier Deferreds from continuing to execute
        their callbacks.
        """
        first = defer.Deferred()
        second = defer.Deferred()
        first.addCallback(lambda ignored: second)
        first.callback(None)
        first.pause()
        second.callback(None)
        result = []
        second.addCallback(result.append)
        self.assertEqual(result, [None])

        A paused Deferred encountered while pushing a result forward through a
        chain does not prevent earlier Deferreds from continuing to execute
        their callbacks.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_defer.py