Use the CO name to construct the entity ID for the virtual IdP
        for the CO.

        The entity ID has the form

        {base_entity_id}/{co_name}

        :type config: satosa.satosa_config.SATOSAConfig
        :type co_name: str
        :rtype: satosa.satosa_config.SATOSAConfig

        :param config: satosa proxy config
        :param co_name: CO name

        :return: config with updated entity ID

def _add_entity_id(self, config, co_name):
        """
        Use the CO name to construct the entity ID for the virtual IdP
        for the CO.

        The entity ID has the form

        {base_entity_id}/{co_name}

        :type config: satosa.satosa_config.SATOSAConfig
        :type co_name: str
        :rtype: satosa.satosa_config.SATOSAConfig

        :param config: satosa proxy config
        :param co_name: CO name

        :return: config with updated entity ID
        """
        base_entity_id = config['entityid']
        co_entity_id = "{}/{}".format(base_entity_id, quote_plus(co_name))
        config['entityid'] = co_entity_id

        return config