teners.
    A middleware calls `next()` function if the chain should continue.

        @app.middleware
        async def simple_middleware(req, resp, next):
            # do something here
            await next()

    This `async_process(req, resp, next)` method is supposed to be invoked only inside bolt-python.
    If you want to avoid the name `next()` in your middleware functions, you can use `next_()` method instead.

        @app.middleware
        async def simple_middleware(req, resp, next_):
     