How to use the ruia.middleware.Middleware function in ruia

self.request_config = self.request_config or {}
        self.headers = self.headers or {}
        self.metadata = self.metadata or {}
        self.kwargs = self.kwargs or {}
        self.request_config = self.request_config or {}

        self.is_async_start = is_async_start
        self.logger = get_logger(name='Spider')
        self.loop = loop
        asyncio.set_event_loop(self.loop)

        # customize middleware
        if isinstance(middleware, list):
            self.middleware = reduce(lambda x, y: x + y, middleware)
        else:
            self.middleware = middleware or Middleware()

        # async queue as a producer
        self.request_queue = asyncio.Queue()

        # semaphore, used for concurrency control
        self.sem = asyncio.Semaphore(self.concurrency)

def __add__(self, other):
        new_middleware = Middleware()
        # asc
        new_middleware.request_middleware.extend(self.request_middleware)
        new_middleware.request_middleware.extend(other.request_middleware)
        # desc
        new_middleware.response_middleware.extend(other.response_middleware)
        new_middleware.response_middleware.extend(self.response_middleware)
        return new_middleware

self.request_config = self.request_config or {}
        self.headers = self.headers or {}
        self.metadata = self.metadata or {}
        self.kwargs = self.kwargs or {}
        self.request_config = self.request_config or {}
        self.request_session = ClientSession()

        self.cancel_tasks = cancel_tasks
        self.is_async_start = is_async_start

        # customize middleware
        if isinstance(middleware, list):
            self.middleware = reduce(lambda x, y: x + y, middleware)
        else:
            self.middleware = middleware or Middleware()

        # async queue as a producer
        self.request_queue = asyncio.Queue()

        # semaphore, used for concurrency control
        self.sem = asyncio.Semaphore(self.concurrency)