_on_close(ws, code, message = '') {
        // Mark websocket poly component as closed
        ws.poly._destroy();

        // Emit 'close' event with parsed message
        ws.poly.emit('close', code, this.#message_parser(message));

        // De-reference the attached polyfill Websocket component so it can ne garbage collected
        delete ws.poly;
    }
Handles 'close' event from uWebsockets.js
@param {uWS.Websocket} ws
@param {Number} code
@param {ArrayBuffer} message