code: function () {
              if (!this.opened()) return;
  
              var cid = this.containerId,
                  scroll = "scroll." + cid,
                  resize = "resize."+cid,
                  orient = "orientationchange."+cid;
  
              // unbind event listeners
              this.container.parents().add(window).each(function () { $(this).off(scroll).off(resize).off(orient); });
  
              this.clearDropdownAlignmentPreference();
  
              $("#select2-drop-mask").hide();
              this.dropdown.removeAttr("id"); // only the active dropdown has the select2-drop id
              this.dropdown.hide();
              this.container.removeClass("select2-dropdown-open");
              this.results.empty();
  
  
              this.clearSearch();
              this.search.removeClass("select2-active");
              this.opts.element.trigger($.Event("select2-close"));
          }
docs: abstract