def METHOD_NAME(self):
    captured = cStringIO()
    json = """{"S3":{"Bucket":"foobar","Prefix":"fiebaz"}}"""
    args = ' --instance-id i-12345678 --owner-aki blah --owner-sak blah --storage %s' % json
    args_list = (self.prefix + args).split()
    _, stderr, _ = self.assert_params_for_cmd(args_list, expected_rc=255)
    expected_err_msg = (
        'Mixing the --storage option with the simple, '
        'scalar options is not recommended'
    )
    self.assertIn(expected_err_msg, stderr)