What is the benefit of having two channels for main and secondary for WS?

[FreerGit]

As title states, trying to understand why websocket has two different channels (/core/src/connectivity/websocket.rs)

pub struct WsSender {
    /// Main websocket connection sender
    main_sender: mpsc::UnboundedSender<Message>,
    /// Secondary websocket connection sender
    secondary_sender: Option<mpsc::UnboundedSender<Message>>,
    /// Cancellation token for service futures
    _cancel: CancellationTokenDropGuard,
}

Is one for hotpath data such as trades/orderbook updates and the secondary one for intra service communication, trigger callback etc?

[siberianguy]

Some exchanges (i. e. Binance) have separate Web Socket endpoints for private and public notifications