The window open handler response must be an object, but was instead of type 'undefined'.

I try using webcontents.setWindowOpenHandler in renderer process, and the console prints "The window open handler response must be an object, but was instead of type 'undefined'."
Here is my code:
```
tab.webcontents.setWindowOpenHandler((details) => {
this.new(details.url);
return {
action: "deny",
}
});
```