JupyterLab 3.5.0调用fromJSON加载模型后单元格操作消失问题求助

我正在开发基于WebSocket的JupyterLab多用户笔记本同步机制，核心操作是通过fromJSON方法合并本地UI单元格数据与服务器端（其他用户编辑的）单元格数据，具体代码如下：

// notebook实例为NotebookPanel
// 合并UI单元格数据与服务器端（其他用户编辑的）单元格数据
// `updatedModel`包含服务器端与用户当前笔记本变更的合并单元格数据
notebook.context.model.fromJSON(updatedModel.content);

遇到的问题 #

• 控制台出现错误
• 单元格操作按钮消失

环境信息 #

• JupyterLab版本：3.5.0

复现代码 #

import {JupyterFrontEnd, JupyterFrontEndPlugin} from "@jupyterlab/application";
import {INotebookTracker, NotebookPanel, NotebookTracker} from "@jupyterlab/notebook";

const testCopyModelFromJSON = (notebookTracker: NotebookTracker) => {
    notebookTracker.widgetAdded.connect((tracker: NotebookTracker, panel: NotebookPanel) => {
        let notebook = panel.content;
        const notebookModel = notebook.model;
        if (!notebookModel) {
            return;
        }
        const model = notebookModel.toJSON();
        notebookModel.fromJSON(model);
    });
}

const plugin: JupyterFrontEndPlugin<void> = {
    id: 'nbsync-extension:plugin',
    autoStart: true,
    requires: [INotebookTracker],
    activate: (app: JupyterFrontEnd, notebookTracker: NotebookTracker) => {
        console.info('nbsync-extension started');
        app.started
            .then(() => {
                testCopyModelFromJSON(notebookTracker);
            });
        app.restored
            .then(() => {
                testCopyModelFromJSON(notebookTracker);
            });
    }
};

export default plugin;

依赖配置 #

"@jupyterlab/application": "^3.5.0",
"@jupyterlab/notebook": "^3.5.0"

请问是否有人遇到过该问题并找到正确从JSON加载笔记本模型的解决方案？

内容的提问来源于stack exchange，提问作者Jake OS