find the OS type (ost) according ost id (prioritary) or ost name
        :param ost_id: the OS type id
        :param ost_name: the OS type name
        :param ost_arch: the OS type architecture
        :return: found OS type or None if not found

def find_ostype(ost_id=None, ost_name=None, ost_arch=None):
        """
        find the OS type (ost) according ost id (prioritary) or ost name
        :param ost_id: the OS type id
        :param ost_name: the OS type name
        :param ost_arch: the OS type architecture
        :return: found OS type or None if not found
        """
        LOGGER.debug("OSTypeService.find_ostype")
        if (ost_id is None or not ost_id) and (ost_name is None or not ost_name) and (ost_arch is None or not ost_arch):
            raise exceptions.ArianeCallParametersError('id and (name, architecture)')

        if (ost_id is not None and ost_id) and ((ost_name is not None and ost_name) or
                                                (ost_arch is not None and ost_arch)):
            LOGGER.warn('OSTypeService.find_ostype - Both id and (name, arc) are defined. Will give you search on id.')
            ost_name = None
            ost_arch = None

        if ((ost_name is not None and ost_name) and (ost_arch is None or not ost_arch)) or\
           ((ost_arch is not None and ost_arch) and (ost_name is None or not ost_name)):
            raise exceptions.ArianeCallParametersError('(name, architecture)')

        params = None
        if ost_id is not None and ost_id:
            params = {'id': ost_id}
        elif ost_name is not None and ost_name and ost_arch is not None and ost_arch:
            params = {'name': ost_name, 'arc': ost_arch}

        ret = None
        if params is not None:
            args = {'http_operation': 'GET', 'operation_path': 'get', 'parameters': params}
            response = OSTypeService.requester.call(args)
            if response.rc == 0:
                ret = OSType.json_2_ostype(response.response_content)
            elif response.rc != 404:
                err_msg = 'OSTypeService.find_ostype - Problem while finding OS Type (id:' + str(ost_id) + \
                          ', name:' + str(ost_name) + '). ' + \
                          'Reason: ' + str(response.response_content) + '-' + str(response.error_message) + \
                          " (" + str(response.rc) + ")"
                LOGGER.warning(
                    err_msg
                )

        return ret