def test_forwardTracebacks(self):
        """
        Chained inlineCallbacks are forwarding the traceback information
        from generator to generator.

        A first simple test with a couple of inline callbacks.
        """

        @inlineCallbacks
        def erroring():
            yield "forcing generator"
            raise Exception('Error Marker')

        @inlineCallbacks
        def calling():
            yield erroring()

        d = calling()
        f = self.failureResultOf(d)
        tb = f.getTraceback()
        self.assertIn("in erroring", tb)
        self.assertIn("in calling", tb)
        self.assertIn("Error Marker", tb)

        Chained inlineCallbacks are forwarding the traceback information
        from generator to generator.

        A first simple test with a couple of inline callbacks.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_inlinecb.py