def assertParseFail(self, cmdline_args, expected_output):
        try:
            self.parser.parse_args(cmdline_args)
        except InterceptedError as err:
            self.assertEqual(err.error_message, expected_output)
        else:
            self.assertFalse("expected parse failure")
Assert the parser fails with the expected message.  Caller
dataset/ETHPy150Open amrdraz/kodr/app/brython/www/src/Lib/test/test_optparse.py/BaseTest.assertParseFail