# File lib/rvg/rvg.rb, line 232
        def draw
            raise StandardError, "draw not permitted in nested RVG objects" if @nested
            @canvas ||= new_canvas    # allow drawing over existing canvas
            gc = Utility::GraphicContext.new
            add_outermost_primitives(gc)
            pp(self) if ENV['debug_rvg']
            print_gc(gc) if ENV['debug_prim']
            gc.draw(@canvas)
            return @canvas
        end