How to set_antialiasing as True in Python?

### Checklist

- [X] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [X] For Python issues, I have tested with the [latest development wheel](http://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](http://www.open3d.org/docs/release/) and the [latest documentation](http://www.open3d.org/docs/latest/) (for `master` branch).

### My Question

Hi all, I've found a function `set_antialiasing` in open3d.visualization.rendering.View class. But there's no example of using it and it seems that there's no constructor for this class. Could you show me how to set the anti-aliasing as True? Thank you so much!