This gist is part of meta-programming with kotlin articles

RefelectionSideEffect.kt

fun main() {
    val singletonKClass = Singleton::class
    singletonKClass.constructors.firstOrNull { it.visibility == KVisibility.PRIVATE }?.also { privateConstructor ->
        /**
         * We give access to private constructor and we can create instance
         * from [Singleton] class [privateConstructor.call] method
         */
        privateConstructor.isAccessible = true
        val singletonNewObject = privateConstructor.call()

        singletonKClass.declaredMemberProperties.firstOrNull { it.visibility == KVisibility.PRIVATE }?.also { dataProperty ->
            /**
             * We give access to private property and we can get value with [dataProperty.get] method.
             */
            dataProperty.isAccessible = true
            dataProperty.get(singletonNewObject).toString().also(::println)
        }
    }
}