def test_addDuringTrigger(self):
        """
        L{_ThreePhaseEvent.addTrigger} should accept C{'during'} as a phase, a
        callable, and some arguments and add the callable with the arguments to
        the during list.
        """
        self.event.addTrigger('during', self.trigger, self.arg)
        self.assertEqual(
            self.event.during,
            [(self.trigger, (self.arg,), {})])

        L{_ThreePhaseEvent.addTrigger} should accept C{'during'} as a phase, a
        callable, and some arguments and add the callable with the arguments to
        the during list.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_internet.py