How to add a WMS to the BaseLayerPicker ?

Hi,
is it possible to add a WMS to the exisiting BaseLayerPicker, instead of creating a new one? If so, how can I add a new service to it?

Looks like when constructing the viewer, you can pass an array of imageryProviderViewModels that will populate the BaseLayerPicker.

https://cesiumjs.org/Cesium/Build/Documentation/Viewer.html?classFilter=Viewer

You could call the createDefaultImageryProviderViewModels and then add one more entry to that array before passing it to the viewer.