code: function (container) {
  		var tiles = Array.prototype.slice.call(container.getElementsByTagName('img')),
  		    i, len, tile;
  
  		for (i = 0, len = tiles.length; i < len; i++) {
  			tile = tiles[i];
  
  			if (!tile.complete) {
  				tile.onload = L.Util.falseFn;
  				tile.onerror = L.Util.falseFn;
  				tile.src = L.Util.emptyImageUrl;
  
  				tile.parentNode.removeChild(tile);
  			}
  		}
  	}
docs: stops loading all tiles in the background layer