Generate the api call functions and attach them to the generated
    RestClient subclass with the name <Service>Client.

def create_rest_client_class(name, apis, BaseClass=RestClient):
    """
    Generate the api call functions and attach them to the generated
    RestClient subclass with the name <Service>Client.
    """

    apis_with_actions = list(itertools.chain.from_iterable([ zip([api] * len(api.actions), api.actions) for api in apis]))

    api_funcs = [create_api_call_func(api, verb) for api, verb in apis_with_actions]
    api_funcs.extend([create_async_api_call_func(api, verb) for api, verb in apis_with_actions])
    api_mapper = dict([ (f.__name__, f) for f in api_funcs ])

    # Adapted from :
    # http://stackoverflow.com/questions/15247075/how-can-i-dynamically-create-derived-classes-from-a-base-class
    def __init__(self, thread_count=_ASYNC_WORKER_THREAD_COUNT, **reqargs):
        BaseClass.__init__(self)
        setattr(self, 'reqargs', read_only_dict(reqargs))
        self._executor = concurrent.futures.ThreadPoolExecutor(thread_count)

    api_mapper['__init__'] =  __init__

    ClientClass = type(_CLIENT_NAME_FMT.format(name), (BaseClass,), api_mapper)
    return ClientClass