class Point {
        public int x,y;

        public Point(int x, int y) {this.x = x;this.y = y;}

        @Override
        public String toString() {
            return "Point{" +
                   "x=" + x +
                   ", y=" + y +
                   '}';
        }
    }

    // Testing ---------------------------------------------

    List<Point> list = new ArrayList<>();

    // populate the list
    list.add(new Point(1,2));

    // printing the list
    System.out.println("Initial list: " + list);

    // getting unmodifiable list
    List<Point> immutableList = Collections.unmodifiableList(list);

    Point p = immutableList.get(0);
    p.x = 10;

    // printing the list
    System.out.println("immutableList: " + immutableList.toString());



// RESULT:
Initial list: [Point{x=1, y=2}]
immutableList: [Point{x=10, y=2}]