code: function (src) {
      var image = _instancePool.get(src);
      if (!image) {
        // Awesome LRU
        image = new Img(src);
        if (_instancePool.length >= kInstancePoolLength) {
          _instancePool.popLeastUsed().destructor();
        }
        _instancePool.push(image.getOriginalSrc(), image);
      }
      return image;
    }
docs: Retrieve an image from the cache
  
  @return {Img}