def METHOD_NAME(
        self, args, device, dataset, model, client_trainer=None, server_aggregator=None
):
    if args.role == "client":
        from .serving import Client
        runner = Client(
            args, device, dataset, model, client_trainer
        )
    elif args.role == "server":
        from .serving import Server
        runner = Server(
            args, device, dataset, model, server_aggregator
        )
    else:
        raise Exception("no such role")
    return runner