class Vector2d extends AbstractVector implements Serializable {

    @Override
    public int hashCode()
    {
        final int prime = 31;
        int result = 1;
        long temp;
        temp = Double.doubleToLongBits(myX);
        result = prime * result + (int)(temp ^ temp >>> 32);
        temp = Double.doubleToLongBits(myY);
        result = prime * result + (int)(temp ^ temp >>> 32);
        return result;
    }

    public  Vector2d(double x, double y);
    public  Vector2d(Vector2d vec);
    public  Vector2d(Vector2i vec);

}