code: public static final Renderer<Double> instance() { // NOPMD it's thread save!
      if (PercentDoubleRenderer.instanceRenderer == null) {
        synchronized (PercentDoubleRenderer.class) {
          if (PercentDoubleRenderer.instanceRenderer == null) {
            PercentDoubleRenderer.instanceRenderer = new PercentDoubleRenderer();
          }
        }
      }
      return PercentDoubleRenderer.instanceRenderer;
    }
docs: returns the instance.
  
  @return CurrencyDoubleRenderer