code: function(callback) {
  
              var self = this,
                  hideEffect = self.options["hideEffect"],
                  hideEffectSpeed = self.options["hideEffectSpeed"],
                  hideEffectOptions = self.options["hideEffectOptions"],
                  isNative = self.options["native"],
                  isMobile = self.isMobile;
  
              // If the drop down is being used and is visible
              if((!isNative && !isMobile) && self.list.is(":visible")) {
  
                  // Triggers a custom "close" event on the original select box
                  self.triggerEvent("close");
  
                  // Uses `no effect`
                  if(hideEffect === "none") {
  
                      // Does not require a callback function because this animation will complete before the call to `scrollToView`
                      self.list.hide();
  
                  }
  
                  // Uses the jQuery `hide` special effect
                  else if(hideEffect === "hide" || hideEffect === "slideUp" || hideEffect === "fadeOut") {
  
                      self.list[hideEffect](hideEffectSpeed);
  
                  }
  
                  // If none of the above options were passed, then a `jqueryUI hide effect` is expected
                  else {
  
                      // Allows for custom hide effects via the [jQueryUI core effects](http://http://jqueryui.com/demos/hide/)
                      self.list.hide(hideEffect, hideEffectOptions, hideEffectSpeed);
  
                  }
  
                  // After the drop down list is done animating
                  self.list.promise().done(function() {
  
                      // Triggers a custom "closed" event when the drop down list is done animating
                      self.triggerEvent("closed");
  
                  });
  
              }
  
              // Provide callback function support
              self._callbackSupport(callback);
  
              // Maintains chainability
              return self;
  
          }
docs: Close ----- Closes the dropdown list options list