def delete_app_server_group_port(self, blb_id, sg_id,
                                     port_list,
                                     client_token=None, config=None):
        """
        delete server group of the specified LoadBalancer,

        :param blb_id:
            id of LoadBalancer
        :type blb_id:string

        :param sg_id:
            id of the server group
        :type sg_id:string

        :param port_list:
            The ports of listeners to be released
        :type port_list:list<string>

        :param client_token:
            If the clientToken is not specified by the user, a random String
            generated by default algorithm will be used.
        :type client_token: string

        :param config:
        :type config: baidubce.BceClientConfiguration

        :return:
        :rtype baidubce.bce_response.BceResponse
        """
        path = utils.append_uri(self.version, 'appblb', blb_id, 'appservergroupport')
        params = {}

        params[b'batchdelete'] = None

        if client_token is None:
            params[b'clientToken'] = generate_client_token()
        else:
            params[b'clientToken'] = client_token

        body = {
            'sgId': compat.convert_to_string(sg_id),
            'portIdList': port_list
        }

        return self._send_request(http_methods.PUT, path,
                                  body=json.dumps(body), params=params,
                                  config=config)