LSP

bad_example.kt

fun main() {
    println("Hello, world!!!")
}

open class Product {
    fun setExpireDate(){
        
    }
}

class Smartphone: Product(){
    fun setExpiredDate(){
        super.setExpireDate()
    }
}

class Grocery: Product(){
    fun setExpiredDate(){
        super.setExpireDate()
    }
}

good_example.kt

fun main() {
    println("Hello, world!!!")
}

open class Product {
    
}

open class FoodProduct: Product(){
    open fun setExpiredDate(){
        //TODO
    }
}

class Smartphone: Product(){
   
}

class Grocery: FoodProduct(){
    override fun setExpiredDate(){
        
    }
}