AdwExpanderRow .ui - can this be included

I’ve got an AdwExpanderRow which has a GtkEditableLabel as a prefix and GtkLabel as a suffix. It’s all created and put together in Python.

I’m now thinking about making a widget template for the expander row but I can’t work out if the prefix and suffix can be added in the .ui file or if it’s something that still has to be done in my Python code?

I plan to set the text for both labels with Python but it would be much neater if I could create the labels and add them to the expander row in the widget template.

Can it be done?

Thank you for any help

That’s what the “GtkBuildable” section in the documentation refers to.