></span>
</code></dt>
<dd>
<details class="source">
<summary>
<span>Expand source code</span>
</summary>
<pre><code class="python">class AsyncMiddleware(metaclass=ABCMeta):
    &#34;&#34;&#34;A middleware can process request data before other middleware and listener functions.&#34;&#34;&#34;

    @abstractmethod
    async def async_process(
        self,
        *,
        req: AsyncBoltRequest,
        resp: BoltResponse,
        # As this method is not supposed to be invoked by bolt-python users,
        