How to use the @jupyter-widgets/base.unpack_models function in @jupyter-widgets/base

private async drawImage(args: any[], buffers: any) {
    const [serializedImage, x, y, width, height] = args;

    const image = await unpack_models(serializedImage, this.widget_manager);

    if (image instanceof CanvasModel || image instanceof MultiCanvasModel) {
      this._drawImage(image.canvas, x, y, width, height);
      return;
    }

    if (image.get('_model_name') == 'ImageModel') {
      // Create the image manually instead of creating an ImageView
      let url: string;
      const format = image.get('format');
      const value = image.get('value');
      if (format !== 'url') {
          const blob = new Blob([value], {type: `image/${format}`});
          url = URL.createObjectURL(blob);
      } else {
          url = (new TextDecoder('utf-8')).decode(value.buffer);

private async _add(payload: any): Promise {
    const { serializedWidget, area, args, id } = payload;
    const model = await unpack_models(serializedWidget, this.widget_manager);
    const view = await this.widget_manager.create_view(model, {});
    const title = await unpack_models(model.get('title'), this.widget_manager);
    const pWidget = view.pWidget;

    pWidget.id = id ?? DOMUtils.createDomID();

    MessageLoop.installMessageHook(pWidget, (handler: any, msg: Message) => {
      switch (msg.type) {
        case 'close-request': {
          const widgets = this.get('_widgets').slice();
          ArrayExt.removeAllWhere(widgets, (w: any) => w.id === handler.id);
          this.set('_widgets', widgets);
          this.save_changes();
          break;
        }
      }

private async _add(payload: any): Promise {
    const { serializedWidget, area, args, id } = payload;
    const model = await unpack_models(serializedWidget, this.widget_manager);
    const view = await this.widget_manager.create_view(model, {});
    const title = await unpack_models(model.get('title'), this.widget_manager);
    const pWidget = view.pWidget;

    pWidget.id = id ?? DOMUtils.createDomID();

    MessageLoop.installMessageHook(pWidget, (handler: any, msg: Message) => {
      switch (msg.type) {
        case 'close-request': {
          const widgets = this.get('_widgets').slice();
          ArrayExt.removeAllWhere(widgets, (w: any) => w.id === handler.id);
          this.set('_widgets', widgets);
          this.save_changes();
          break;
        }
      }
      return true;
    });