def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def test_login(self, mock_login_with_token, mock_input, mock_open_url):
        quilt3.login()

        url = quilt3.session.get_registry_url()

        mock_open_url.assert_called_with(f'{url}/login')
        mock_login_with_token.assert_called_with('123456')