docs: @Override
  	public void normalize(Vector3D v1) {
          double norm;
          norm = 1./Math.sqrt(v1.getX()*v1.getX() + v1.getY()*v1.getY() + v1.getZ()*v1.getZ());
          this.x = (int)(v1.getX()*norm);
          this.y = (int)(v1.getY()*norm);
          this.z = (int)(v1.getZ()*norm);
  	}