GameView constructor with given gameMode and levelManager
Source
GameView(GameMode this._gameMode, LevelManager this._levelManager) {
    onInput = _inputEvent.stream.asBroadcastStream();
    onSelectLevel = _selectLevelEvent.stream.asBroadcastStream();
    _mainElement.classes.add("loaded"); // Indicate that the game program has loaded
    _setupListeners();
}