rwl.readLock().unlock(); return result;
    public RGBBuffer render(PlaneDef pd)            throws IOException, QuantizationException    {        RGBBuffer result = null;        rwl.readLock().lock();         {            if (renderer == null)                throw new IllegalStateException(NULL_RENDERER);                        result = renderer.render(pd);        }        rwl.readLock().unlock();        return result;    }