code: function() {
              var cid = this.containerId, selector = this.containerSelector,
                  scroll = "scroll." + cid, resize = "resize." + cid;
  
              this.container.parents().each(function() {
                  $(this).bind(scroll, function() {
                      var s2 = $(selector);
                      if (s2.length == 0) {
                          $(this).unbind(scroll);
                      }
                      s2.select2("close");
                  });
              });
  
              $(window).bind(resize, function() {
                  var s2 = $(selector);
                  if (s2.length == 0) {
                      $(window).unbind(resize);
                  }
                  s2.select2("close");
              });
  
              this.clearDropdownAlignmentPreference();
  
              if (this.search.val() === " ") { this.search.val(""); }
  
              this.container.addClass("select2-dropdown-open").addClass("select2-container-active");
  
              this.updateResults(true);
  
              if(this.dropdown[0] !== this.body().children().last()[0]) {
                  this.dropdown.detach().appendTo(this.body());
              }
  
              this.dropdown.show();
  
              this.positionDropdown();
              this.dropdown.addClass("select2-drop-active");
  
              this.ensureHighlightVisible();
  
              this.focusSearch();
          }
docs: Performs the opening of the dropdown
   abstract