DesignPattern.kt

fun main() {
    val field = GameField("Brazil", 80)
    val grass = GrassGameFieldDecorator(field)
    val wood = WoodGameFieldDecorator(grass)

    println("Maintenance started on ${wood.location} that has ${wood.size} km²")
    wood.maintain()
}

open class GameField (
    val location: String,
    // km-squared size of the field... because yes...
    val size: Int
) {
    open fun maintain() {
        println("Doing nothing more... It is perfect")
    }
}

abstract class GameFieldDecorator (
    field: GameField
) : GameField(field.location, field.size)

class GrassGameFieldDecorator (
    private val field: GameField
) : GameFieldDecorator(field) {
    override fun maintain() {
        println("Checking grass for holes...")
        field.maintain()
    }
}

class WoodGameFieldDecorator (
    private val field: GameField
) : GameFieldDecorator(field) {
    override fun maintain() {
        println("Checking field for missing woods...")
        field.maintain()
    }
}

You can test this here: https://pl.kotl.in/Ofmr2abOC
Or... You can copy + paste this code on Kotlin Playground yourself