code: function Feature() {
        var _this;
  
        var ua = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : null;
        var flags = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
        var cssFlagsPrefix = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 'feature';
  
        _classCallCheck(this, Feature);
  
        _this = _possibleConstructorReturn(this, _getPrototypeOf(Feature).call(this, ua, flags, cssFlagsPrefix));
  
        _this._createTestElements();
  
        _this.addEventListener = _this.getAddEventListener();
        _this.asyncScript = _this.getAsyncScript();
        _this.battery = _this.getBattery();
        _this.cors = _this.getCors();
        _this.deferScript = _this.getDeferScript();
        _this.file = _this.getFile();
        _this.fileSystem = _this.getFileSystem();
        _this.fullscreen = _this.getFullscreen();
        _this.fullscreenKeyboard = _this.getFullscreenKeyboard();
        _this.geolocation = _this.getGeolocation();
        _this.historyAPI = _this.getHistoryAPI();
        _this.littleEndian = _this.getLittleEndian();
        _this.localStorage = _this.getLocalStorage();
        _this.matchMedia = _this.getMatchMedia();
        _this.querySelector = _this.getQuerySelector();
        _this.querySelectorAll = _this.getQuerySelectorAll();
        _this.serviceWorker = _this.getServiceWorker();
        _this.typedArray = _this.getTypedArray();
        _this.userMedia = _this.getUserMedia();
        _this.vibration = _this.getVibration();
        _this.worker = _this.getWorker();
        return _this;
      }
docs: Creates an instance of Feature.
  @param {any} [ua=null]
  @param {any} [flags={}]
  @param {string} [cssFlagsPrefix='feature']
  
  @memberOf Feature