Drawing shape layers in Javascript

Anyone have any examples of drawing shape layers through Javascript?  I'm able to make a new shape layer in my comp:

myShape = cmp.layers.addShape();

but then I'm not sure how to proceed to add any contents to the shape.  The scripting guide is vague here saying I need to add properties to it like the shape and fill and such, but ShapeLayer says nothing and refers to the parent AVLayer class.

I'm assuming I need to add PropertyGroups to the shape layer but I'm not sure what properties to even add.

Any insight appreciated as I continue to poke around hoping to hit the right thing