def test_attributeAccess(self):
        """
        A sentence attribute gets the correct value, and accessing an
        unset attribute (which is specified as being a valid sentence
        attribute) gets L{None}.
        """
        thisSentinel = object()
        sentence = self.sentenceClass({sentinelValueOne: thisSentinel})
        self.assertEqual(getattr(sentence, sentinelValueOne), thisSentinel)
        self.assertIsNone(getattr(sentence, sentinelValueTwo))

        A sentence attribute gets the correct value, and accessing an
        unset attribute (which is specified as being a valid sentence
        attribute) gets L{None}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/positioning/test/test_sentence.py