find the subnet according subnet id (prioritary) or subnet name
        :param sb_id: the subnet id
        :param sb_name: the subnet name
        :return: found subnet or None if not found

def find_subnet(sb_id=None, sb_name=None):
        """
        find the subnet according subnet id (prioritary) or subnet name
        :param sb_id: the subnet id
        :param sb_name: the subnet name
        :return: found subnet or None if not found
        """
        LOGGER.debug("SubnetService.find_subnet")
        if (sb_id is None or not sb_id) and (sb_name is None or not sb_name):
            raise exceptions.ArianeCallParametersError('id and name')

        if (sb_id is not None and sb_id) and (sb_name is not None and sb_name):
            LOGGER.warn('Both id and name are defined. Will give you search on id.')
            sb_name = None

        params = None
        if sb_id is not None and sb_id:
            params = {'id': sb_id}
        elif sb_name is not None and sb_name:
            params = {'name': sb_name}

        ret = None
        if params is not None:
            args = {'http_operation': 'GET', 'operation_path': 'get', 'parameters': params}
            response = SubnetService.requester.call(args)
            if response.rc == 0:
                ret = Subnet.json_2_subnet(response.response_content)
            elif response.rc != 404:
                err_msg = 'SubnetService.find_subnet - Problem while finding subnet (id:' + str(sb_id) + \
                          ', name:' + str(sb_name) + '). ' + \
                          '. Reason: ' + str(response.response_content) + '-' + str(response.error_message) + \
                          " (" + str(response.rc) + ")"
                LOGGER.warning(err_msg)

        return ret