docs: function (relatedTarget) {
  
              if (this.callbackID) {
                  ariaCoreTimer.cancelCallback(this.callbackID);
              }
              if (this._popup != null) {
                  if (!ariaUtilsDom.isAncestor(relatedTarget, this._popup.domElement)) {
  
                      if (this._popup) {
                          this._popup.closeOnMouseOut();
                      }
                  }
              }
              this.callbackID = null;
  
          }