Generate API root URL without resources
        :param protocol: Web protocol [HTTP | HTTPS] (string)
        :param host: Hostname or IP (string)
        :param port: Service port (string)
        :return: ROOT url

def _generate_url_root(protocol, host, port):
        """
        Generate API root URL without resources
        :param protocol: Web protocol [HTTP | HTTPS] (string)
        :param host: Hostname or IP (string)
        :param port: Service port (string)
        :return: ROOT url
        """
        return URL_ROOT_PATTERN.format(protocol=protocol, host=host, port=port)