def METHOD_NAME(request_cls):
    """ Extract a request's response class using the mapping found in the module defining the request's service """
    for req_cls in request_cls.mro():
        module = sys.modules[req_cls.__module__]
        if hasattr(module, 'action_mapping'):
            return module.action_mapping[(request_cls._action, request_cls._version)][1]
        elif hasattr(module, 'response_mapping'):
            return module.response_mapping[req_cls]
    raise TypeError('no response class!')