def test_extraneousAttributes(self):
        """
        L{endpoints._ProcessEndpointTransport} filters out extraneous
        attributes of its underlying transport, to present a more consistent
        cross-platform view of subprocesses and prevent accidental
        dependencies.
        """
        self.process.pipes = []
        self.assertRaises(AttributeError,
                          getattr, self.endpointTransport, 'pipes')

        L{endpoints._ProcessEndpointTransport} filters out extraneous
        attributes of its underlying transport, to present a more consistent
        cross-platform view of subprocesses and prevent accidental
        dependencies.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_endpoints.py