code: function(show) {
              Dom.setStyle(this.element, "visibility", (show) ? "visible" : "hidden");
              var hiddenClass = Overlay.CSS_HIDDEN;
  
              if (show) {
                  Dom.removeClass(this.element, hiddenClass);
              } else {
                  Dom.addClass(this.element, hiddenClass);
              }
          }
docs: Internal implementation to set the visibility of the overlay in the DOM.
  
  @method _setDomVisibility
  @param {boolean} visible Whether to show or hide the Overlay's outer element
  @protected