class MG_DrawingRenderable extends MG_Drawing {
    ArrayList<MG_I_DrawingRenderable> renderable = new ArrayList<MG_I_DrawingRenderable>();
    @Override
        public void addElement(MG_I_DrawingElement el) {
            super.addElement(el);
        if(el implements MG_I_DrawingRenderable) {
            renderable.add((MG_I_DrawingRenderable)el);
        }
        }
    public void render() {
        for(MG_I_DrawingRenderable el : renderable) {
            el.render();
        }
    }
}