code: function (layer) {
          if (!layer.getMapContainer) return [];
          // find all images in layer div
          var all = Array.prototype.slice.call(layer.getMapContainer().getElementsByTagName('img'));
          var len = all.length,
              images = [],
              tileSize = layer.tileSize,
              //zoom = "z=" + layer.map.getZoom(),
              i, tile;
  
          // filter google tiles with current zoom among all
          for (i = 0; i < len; i++) {
              tile = all[i];
              if (tile.src.search("google") != -1 /*&& tile.src.search(zoom) != -1*/ && tile.width == tileSize.w && tile.height == tileSize.h) {
                  images.push(tile);
              }
          }
  
          return images;
      }
docs: private