@Override
    public String toString() {
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append("x=");
        stringBuilder.append(this.x);
        stringBuilder.append(", y=");
        stringBuilder.append(this.y);
        return stringBuilder.toString();
    }
@Test
    public void toStringTest() {
        Point point = new Point(1, 2);
        Assert.assertEquals(POINT_TO_STRING, point.toString());
    }