Singleton implementation for Kotlin (took it from Google sample)

KotlinSingleton.kt

/**
 * Created by Prasanna on 28-11-2018.
 */
class KotlinSingleton {
    companion object {
        @Volatile
        private var INSTANCE: KotlinSingleton? = null

        fun getInstance(id: String): KotlinSingleton = INSTANCE ?: synchronized(this) {
            INSTANCE ?: buildInstance(id).also { INSTANCE = it }
        }

        private fun buildInstance(id: String) = KotlinSingleton()
    }
}