lsp_isp__lsp_know_more.kt

class MobileEngineer : SoftwareEngineer() {

    override fun calculateSeniority(yearsInBusiness: Int): Int {
        if (yearsInBusiness >= 15) {
            return ULTRA_SENIOR
        }
        return super.calculateSeniority(yearsInBusiness)
    }

    companion object {
        const val ULTRA_SENIOR = 3
    }
}

// which leads in:

fun printSeniority(engineer: SoftwareEngineer, yearsInBusiness: Int) {
    val seniority = engineer.calculateSeniority(yearsInBusiness)
    val label = when (seniority) {
        MobileEngineer.ULTRA_SENIOR -> "ultra senior" // printSeniority is forced to know about MobileEngineer
        SoftwareEngineer.JUNIOR -> "junior"
        SoftwareEngineer.MID -> "mid"
        else -> "senior"
    }

    println("This is a $label engineer")
}