Function serve_jsonl_connection 

pub async fn serve_jsonl_connection<Req, Resp, F, Fut, InvalidResp>(
    stream: UnixStream,
    handler: F,
    invalid_response: InvalidResp,
) -> Result<()>
where
    Req: DeserializeOwned,
    Resp: Serialize,
    F: Fn(Req) -> Fut,
    Fut: Future<Output = Resp>,
    InvalidResp: Fn(Error) -> Resp,