def yaml(self):
        return yaml.dump(self.serialized, default_flow_style=False,
                         encoding=None)
def check_bad_url_raises(value):
    try:
        inputs.url(value)
        assert False, "shouldn't get here"
    except ValueError as e:
        assert_equal(six.text_type(e), u"{0} is not a valid URL".format(value))