setup method
Method to setup the TextTrack event listeners on a TextTrack list (TextTracks)
Implementation
void setup(TextTracks trackListToWrap) {
_wrappedTrackList = trackListToWrap;
innerList = trackListToWrap;
_wrappedTrackList?.addEventListener(TextTracksEventTypes.ADDTRACK, forwardingkEventListener);
_wrappedTrackList?.addEventListener(TextTracksEventTypes.REMOVETRACK, forwardingkEventListener);
_wrappedTrackList?.addEventListener(TextTracksEventTypes.CHANGE, forwardingkEventListener);
}