Output a mask?

Hi

I'm trying to figure out how to use opencv4node to render a mask rather than a box (which I have working).

I'm using a tensorflow model - mask_rcnn_inception_v2_coco and assume I need to write something like the following bit of python:

(boxes, masks) = net.forward(["detection_out_final", "detection_masks"])

... instead of:

let out = this.net.forward()

... which is what I normally do.

I'm stuck... any examples or code snippets would be gratefully received :-)