abstract class ReceiverClass {
	open fun String.onSomethingHappened() {
		println(this)
	}
}

class Child : ReceiverClass() {
	override fun String.onSomethingHappened() {
		with(this@Child as ReceiverClass){
			this@onSomethingHappened.onSomethingHappened()
			println("hello world")
		}
	}
}