def test_nonGeneratorReturnValue(self):
        """
        Ensure that C{TypeError} with a message about L{inlineCallbacks} is
        raised when a non-generator calls L{returnValue}.
        """
        def _noYield():
            returnValue(5)
        _noYield = inlineCallbacks(_noYield)

        self.assertIn("inlineCallbacks",
            str(self.assertRaises(TypeError, _noYield)))

        Ensure that C{TypeError} with a message about L{inlineCallbacks} is
        raised when a non-generator calls L{returnValue}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_defgen.py