code: function( item ) {
          $.console.assert(item, "[World.removeItem] item is required");
  
          var index = $.indexOf(this._items, item );
          if ( index === -1 ) {
              return;
          }
  
          item.removeHandler('bounds-change', this._delegatedFigureSizes);
          item.removeHandler('clip-change', this._delegatedFigureSizes);
          item.destroy();
          this._items.splice( index, 1 );
          this._figureSizes();
          this._needsDraw = true;
          this._raiseRemoveItem(item);
      }
docs: Remove an item.
  @param {OpenSeadragon.TiledImage} item - The item to remove.
  @fires OpenSeadragon.World.event:remove-item
  @fires OpenSeadragon.World.event:metrics-change