class Vectors {

    public static Vector rotateAroundZAxis(Vector vector, double angle) {
        double cos = cos(angle);
        double sin = sin(angle);
        double x = vector.getX() * cos - vector.getY() * sin;
        double y = vector.getX() * sin + vector.getY() * cos;
        
        return vector.setX(x).setY(y);
    }

}