virtual void add(const Renderable &) = 0;
virtual void remove(const Renderable &) = 0;
using Renderable::render;
virtual void render(const Tag & = Tag()) const;
virtual void add(const Renderable &) = 0;
virtual void remove(const Renderable &) = 0;
using Renderable::render;
virtual void render(const Tag & = Tag()) const;