nl_tokens: Create an instance of this class .
pl_tokens: function VideoTrackList ( ) { var _this , _ret ; var tracks = arguments . length > 0 && arguments [ 0 ] !== undefined ? arguments [ 0 ] : [ ] ; classCallCheck ( this , VideoTrackList ) ; var list = void 0 ; // make sure only 1 track is enabled // sorted from last index to first index for ( var i = tracks . length - 1 ; i >= 0 ; i -- ) { if ( tracks [ i ] . selected ) { disableOthers$1 ( tracks , tracks [ i ] ) ; <mask> ; } } // IE8 forces us to implement inheritance ourselves // as it does not support Object.defineProperty properly if ( IS_IE8 ) { list = document . createElement ( 'custom' ) ; for ( var prop in TrackList . prototype ) { if ( prop !== 'constructor' ) { list [ prop ] = TrackList . prototype [ prop ] ; } } for ( var _prop in VideoTrackList . prototype ) { if ( _prop !== 'constructor' ) { list [ _prop ] = VideoTrackList . prototype [ _prop ] ; } } } list = ( _this = possibleConstructorReturn ( this , _TrackList . call ( this , tracks , list ) ) , _this ) ; list . changing_ = false ; /**
       * @member {number} VideoTrackList#selectedIndex
       *         The current index of the selected {@link VideoTrack`}.
       */ Object . defineProperty ( list , 'selectedIndex' , { get : function get$$1 ( ) { for ( var _i = 0 ; _i < this . length ; _i ++ ) { if ( this [ _i ] . selected ) { return _i ; } } return - 1 ; } , set : function set$$1 ( ) { } } ) ; return _ret = list , possibleConstructorReturn ( _this , _ret ) ; }