_on_message(ws, message = '', is_binary) {
        // Emit 'message' event with parsed message from uWS
        ws.poly.emit('message', this.#message_parser(message), is_binary);
    }
Handles 'message' event from uWebsockets.js
@private
@param {uWS.Websocket} ws
@param {ArrayBuffer} message
@param {Boolean} is_binary