def test_exitfirst(self):
        """
        Passing C{--exitfirst} wraps the reporter with a
        L{reporter._ExitWrapper} that stops on any non-success.
        """
        self.options.parseOptions(["--exitfirst"])
        runner = trial._makeRunner(self.options)
        self.assertTrue(runner._exitFirst)

        Passing C{--exitfirst} wraps the reporter with a
        L{reporter._ExitWrapper} that stops on any non-success.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/test/test_script.py