} finally { rwl.writeLock().unlock();
    public void setRGBA(int w, int red, int green, int blue, int alpha)    {        rwl.writeLock().lock();        {            if (renderer == null)                throw new IllegalStateException(NULL_RENDERER);            renderer.setRGBA(w, red, green, blue, alpha);        }        rwl.writeLock().unlock();    }