code: function() {
  
              var self = this,
                  moveToOption = self.list.is(":visible") || !self.options["keydownOpen"];
  
              return {
  
                  "down": function() {
  
                      // If the plugin options allow keyboard navigation
                      if (self.moveDown && moveToOption) {
  
                          self.moveDown();
  
                      }
  
                  },
  
                  "up": function() {
  
                       // If the plugin options allow keyboard navigation
                      if (self.moveUp && moveToOption) {
  
                          self.moveUp();
  
                      }
  
                  },
  
                  "enter": function() {
  
                      var activeElem = self.listItems.eq(self.currentFocus);
  
                      // Updates the dropdown list value
                      self._update(activeElem);
  
                      if (activeElem.attr("data-preventclose") !== "true") {
  
                          // Closes the drop down list options list
                          self.close();
  
                      }
  
                      // Triggers the `enter` events on the original select box
                      self.triggerEvent("enter");
  
                  },
  
                  "tab": function() {
  
                      // Triggers the custom `tab-blur` event on the original select box
                      self.triggerEvent("tab-blur");
  
                      // Closes the drop down list
                      self.close();
  
                  },
  
                  "backspace": function() {
  
                      // Triggers the custom `backspace` event on the original select box
                      self.triggerEvent("backspace");
  
                  },
  
                  "esc": function() {
  
                      // Closes the dropdown options list
                      self.close();
  
                  }
  
              };
  
          }
docs: _Key Down Methods ----------------- Methods to use when the keydown event is triggered