code: public static boolean detectIE11() {
      String ua = DomGlobal.window.navigator.userAgent;
      if (ua.indexOf("MSIE ") > 0) {
        return true;
      }
      return ua.indexOf("Trident/") > 0;
    }
docs: checks weather the current browser is IE or not.
  <p>
  IE 10
  ua = 'Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.2; Trident/6.0)';
  <p>
  IE 11
  ua = 'Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv:11.0) like Gecko';
  <p>
  Edge 12 (Spartan)
  ua = 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.71 Safari/537.36 Edge/12.0';
  <p>
  Edge 13
  ua = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2486.0 Safari/537.36 Edge/13.10586';
  
  @return true: is IE