How to access trimmed curves in BrepFace (2D parameter space) using JavaScript?

Hi,
I'm looking for a way to access the trimmed curves of a `BrepFace` using the JavaScript library (rhino3dm.js). 
Specifically, I would like to obtain the curves in the 2D parameter space (UV domain), rather than the 3D edge curves.

Is there a recommended method or API to retrieve these 2D parameter-space curves?

Thanks in advance!