https://medium.com/@sharinogan/oop-object-oriented-programming-%E0%B8%AA%E0%B8%87%E0%B8%AA%E0%B8%B1%E0%B8%A2%E0%B8%88%E0%B8%B1%E0%B8%87-%E0%B8%A1%E0%B8%B2%E0%B8%97%E0%B8%B2%E0%B8%87%E0%B8%99%E0%B8%B5%E0%B9%89-82df6878cdf1
