class Impl : A, B {
  constructor(b: B) /* primary */ {
    super/*Any*/()
    /* <init>() */

  }

  private /* final field */ val $$delegate_0: B = b
  override val size: Int
    override get(): Int {
      return <this>.#$$delegate_0.<get-size>()
    }

  override fun add(element: @FlexibleNullability String?): Boolean {
    return <this>.#$$delegate_0.add(element = element)
  }

  override fun addAll(elements: Collection<@FlexibleNullability String?>): Boolean {
    return <this>.#$$delegate_0.addAll(elements = elements)
  }

  override fun clear() {
    <this>.#$$delegate_0.clear()
  }

  override operator fun contains(element: @FlexibleNullability String?): Boolean {
    return <this>.#$$delegate_0.contains(element = element)
  }

  override fun containsAll(elements: Collection<@FlexibleNullability String?>): Boolean {
    return <this>.#$$delegate_0.containsAll(elements = elements)
  }

  override fun isEmpty(): Boolean {
    return <this>.#$$delegate_0.isEmpty()
  }

  override operator fun iterator(): MutableIterator<@FlexibleNullability String?> {
    return <this>.#$$delegate_0.iterator()
  }

  override fun remove(element: @FlexibleNullability String?): Boolean {
    return <this>.#$$delegate_0.remove(element = element)
  }

  override fun removeAll(elements: Collection<@FlexibleNullability String?>): Boolean {
    return <this>.#$$delegate_0.removeAll(elements = elements)
  }

  override fun retainAll(elements: Collection<@FlexibleNullability String?>): Boolean {
    return <this>.#$$delegate_0.retainAll(elements = elements)
  }

}

fun box(): String {
  return "OK"
}