wheel = new BallAxis(Axis.Identifier.SLIDER);
if(numAxes > 2) { wheel = new BallAxis(Axis.Identifier.SLIDER); }
        public BallImpl() {            super(DirectInputMouse.this.getName() + " ball");            x = new BallAxis(Axis.Identifier.X);            y = new BallAxis(Axis.Identifier.Y);            wheel = new BallAxis(Axis.Identifier.SLIDER);        }