function CellRangeDecorator(grid, options) {
    var _elem;
    var _defaults = {
      selectionCssClass: 'slick-range-decorator',
      selectionCss: {
        "zIndex": "9999",
        "border": "2px dashed red"
      }
    };

    options = $.extend(true, {}, _defaults, options);


    function show(range) {
      if (!_elem) {
        _elem = $("<div></div>", {css: options.selectionCss})
            .addClass(options.selectionCssClass)
            .css("position", "absolute")
            .appendTo(grid.getCanvasNode());
      }

      var from = grid.getCellNodeBox(range.fromRow, range.fromCell);
      var to = grid.getCellNodeBox(range.toRow, range.toCell);

      _elem.css({
        top: from.top - 1,
        left: from.left - 1,
        height: to.bottom - from.top - 2,
        width: to.right - from.left - 2
      });

      return _elem;
    }

    function hide() {
      if (_elem) {
        _elem.remove();
        _elem = null;
      }
    }

    $.extend(this, {
      "show": show,
      "hide": hide
    });
  }
Displays an overlay on top of a given cell range.

TODO:
Currently, it blocks mouse events to DOM nodes behind it.
Use FF and WebKit-specific "pointer-events" CSS style, or some kind of event forwarding.
Could also construct the borders separately using 4 individual DIVs.

@param {Grid} grid
@param {Object} options