public boolean deleteElementFieldView(ElementFieldView element) {
        if (element instanceof BallView) {
            return _ballsView.remove((BallView) element);
        } else if (element instanceof BoundaryView) {
            return _boundariesView.remove((BoundaryView) element);
        } else if (element instanceof RacketView) {
            _racketView = null;
            return true;
        } else if (element instanceof DestructibleBrickView) {
            return _dBricksView.remove((DestructibleBrickView) element);
        } else if (element instanceof IndestructibleBrickView) {
            return _iBricksView.remove((IndestructibleBrickView) element);
        }
        return false;
    }