code: function ElementUtilities_maintainFocus(callback) {
              var focusedElement = _Global.document.activeElement;
              callback();
              exports._trySetActiveOnAnyElement(focusedElement);
          }
docs: Ensures that the same element has focus before and after *callback* is called. Useful if moving focus is an unintentional side effect of *callback*. For example, this could happen if *callback* removes and reinserts elements to the DOM.