Method check_exit_message

Lib/test/test_sys.py:268–272

(code, expected, **env_vars)

        self.assertEqual(err, b'')

        def check_exit_message(code, expected, **env_vars):
            rc, out, err = assert_python_failure('-c', code, **env_vars)
            self.assertEqual(rc, 1)
            self.assertEqual(out, b'')
            self.assertStartsWith(err, expected)

        # test that stderr buffer is flushed before the exit message is written
        # into stderr