Function subscribe 

pub(super) async fn subscribe<B, W, T>(
    client: &Arc<Client<B, W>>,
    quic_conn: &QuicConn,
    subscriptions: &Subscriptions,
    unsub_chans: &Mutex<HashMap<SubscriptionID, Sender<Value>>>,
    method: &str,
    params: T,
) -> Result<Arc<Subscription>>
where
    B: JsonRpcCodec,
    W: WsCodec,
    T: Serialize + DeserializeOwned,