code: function Flyout_addFirstDiv() {
                      var firstDiv = _Global.document.createElement("div");
                      firstDiv.className = _Constants.firstDivClass;
                      firstDiv.style.display = "inline";
                      firstDiv.setAttribute("role", "menuitem");
                      firstDiv.setAttribute("aria-hidden", "true");
  
                      // add to beginning
                      if (this._element.children[0]) {
                          this._element.insertBefore(firstDiv, this._element.children[0]);
                      } else {
                          this._element.appendChild(firstDiv);
                      }
  
                      var that = this;
                      _ElementUtilities._addEventListener(firstDiv, "focusin", function () { that._focusOnLastFocusableElementOrThis(); }, false);
  
                      return firstDiv;
                  }
docs: Create and add a new first div as the first child