code: function(element) {
              var $element = $(element);
              if ($element.is(':selected')) {
                  $element.prop('selected', true);
              }
  
              // Support the label attribute on options.
              var label = this.options.optionLabel(element);
              var value = $element.val();
              var inputType = this.options.multiple ? "checkbox" : "radio";
  
              var $li = $(this.options.templates.li);
              var $label = $('label', $li);
              $label.addClass(inputType);
  
              if (this.options.enableHTML) {
                  $label.html(" " + label);
              }
              else {
                  $label.text(" " + label);
              }
  
              var $checkbox = $('<input/>').attr('type', inputType);
  
              if (this.options.checkboxName) {
                  $checkbox.attr('name', this.options.checkboxName);
              }
              $label.prepend($checkbox);
  
              var selected = $element.prop('selected') || false;
              $checkbox.val(value);
  
              if (value === this.options.selectAllValue) {
                  $li.addClass("multiselect-item multiselect-all");
                  $checkbox.parent().parent()
                      .addClass('multiselect-all');
              }
  
              $label.attr('title', $element.attr('title'));
  
              this.$ul.append($li);
  
              if ($element.is(':disabled')) {
                  $checkbox.attr('disabled', 'disabled')
                      .prop('disabled', true)
                      .closest('a')
                      .attr("tabindex", "-1")
                      .closest('li')
                      .addClass('disabled');
              }
  
              $checkbox.prop('checked', selected);
  
              if (selected && this.options.selectedClass) {
                  $checkbox.closest('li')
                      .addClass(this.options.selectedClass);
              }
          }
docs: Create an option using the given select option.
  
  @param {jQuery} element