code: function Flyout_addFinalDiv() {
                      var finalDiv = _Global.document.createElement("div");
                      finalDiv.className = _Constants.finalDivClass;
                      finalDiv.style.display = "inline";
                      finalDiv.setAttribute("role", "menuitem");
                      finalDiv.setAttribute("aria-hidden", "true");
  
                      this._element.appendChild(finalDiv);
                      var that = this;
                      _ElementUtilities._addEventListener(finalDiv, "focusin", function () { that._focusOnFirstFocusableElementOrThis(); }, false);
  
                      return finalDiv;
                  }
docs: Create and add a new final div as the last child