package com.rsk interface Signatory { fun sign() } open class Person(val name: String, var age: Int, var isMarried: Boolean = false): Signatory { override fun sign() = println("${name}: I can sign documents") init { println("Person init") } companion object { @JvmStatic fun main(args: Array<String>) { val p = Person(name="Wan2", age=21) p.sign() } } }