Scruffy - how to assign SVG Builder object

hi

I’m trying to render rectangles and lines. Right now I’m using
Scruffy::Layers::Base to render, but the method

draw(svg,coords,options={})

is a little confusing.

“svg: a Builder object to use for creating SVG code.”

Anyone has idea of what parameter to pass?
I’ve googled a lot but still got no answers or tutorials.

Best regards.
Kevin