def test_addFailureSendsSubunitAddFailure(self):
        """
        SubunitReporter.addFailure() sends the subunit 'addFailure' message.
        """
        try:
            self.fail('hello')
        except self.failureException:
            failure = sys.exc_info()
        self.assertForwardsToSubunit('addFailure', self.test, failure)

        SubunitReporter.addFailure() sends the subunit 'addFailure' message.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/test/test_reporter.py