filter some requests in addon without using regexp filters

[Devhercule]

Hi,

Is it possible with the mitmproxy to be able (according to a defined condition) to prevent a request, not send it to the server and optionnaly make a response directly to the client? knowing that I have stream=True

I tried to do this :
flow.response = mitmproxy.http.Response.make(403, b"Hello World", {"Content-Type": "text/html"})
But it generates this error :
Can't set a response and enable streaming at the same time.

I would like to verify the condition and filter the request satisfying the condition (abort it for example)

Thank you