code: public void render() {
  		if (list == -1) {
  			throw new RuntimeException("Attempt to render cached operations that have been destroyed");
  		}
  		
  		SlickCallable.enterSafeBlock();
  		GL.glCallList(list);
  		SlickCallable.leaveSafeBlock();
  	}
docs: Render the cached operations. Note that this doesn't call the operations, but
  rather calls the cached version