containsAll 
  Checks if all elements in the specified collection are contained in this collection.
Allows to overcome type-safety restriction of containsAll that requires to pass a collection of type Collection<E>.
Since Kotlin
1.0Samples
import kotlin.test.*
fun main() { 
   //sampleStart 
   val collection = mutableListOf('a', 'b')
val test = listOf('a', 'b', 'c')
println("collection.containsAll(test) is ${collection.containsAll(test)}") // false
collection.add('c')
println("collection.containsAll(test) is ${collection.containsAll(test)}") // true 
   //sampleEnd
}