https://www.redressonline.com/2018/10/%d8%a3%d9%8a%d9%86-%d9%8a%d9%83%d9%85%d9%86-%d8%a7%d9%84%d8%b9%d9%8a%d8%a8%d8%9f-where-does-the-defect-lie/