We have an existing application build using ArcGIS .NET Runtime 10.2.7. We are trying to port the logic to the new 'Quartz' release (v100.0).
The issue I'm facing is trying to port the following logic. We have a url to an existing feature service layer that I want to create an item for (with tags and description).

The problem here seems to be that:
- Tags and Url properties on PortalItem are now read-only
- ArcGISPortal object doesn't seem to have a method for saving/creating items on portal (nor does there seem to be any equivalent method on ArcGISPortal
Map and FeatureCollection seem to have a 'SaveAs' method that allows you to save Maps and FeatureCollection as items in a Portal, but in this case I just want to create an item that is a link to an existing Feature Service (layer).
Any help would be greatly appreciated.
Thank you!