// CHECK:
//   Mangled name: Impl
//   Public signature: /Impl|null[0]
class Impl : A, B {
  // CHECK:
  //   Mangled name: Impl#<init>(Foo.B){}
  //   Public signature: /Impl.<init>|1084968671839233134[0]
  //   Public signature debug description: <init>(Foo.B){}
  constructor(b: B) /* primary */

  // CHECK JVM_IR:
  //   Mangled name: Impl#add(kotlin.String?){}kotlin.Boolean
  //   Public signature: /Impl.add|-2525808668243873976[0]
  //   Public signature debug description: add(kotlin.String?){}kotlin.Boolean
  override fun add(element: String?): Boolean

  // CHECK JVM_IR:
  //   Mangled name: Impl#addAll(kotlin.collections.Collection<kotlin.String?>){}kotlin.Boolean
  //   Public signature: /Impl.addAll|-3089528969221638255[0]
  //   Public signature debug description: addAll(kotlin.collections.Collection<kotlin.String?>){}kotlin.Boolean
  override fun addAll(elements: Collection<String?>): Boolean

  // CHECK:
  //   Mangled name: Impl#clear(){}
  //   Public signature: /Impl.clear|-6446868449915108923[0]
  //   Public signature debug description: clear(){}
  override fun clear(): Unit

  // CHECK JVM_IR:
  //   Mangled name: Impl#contains(kotlin.String?){}kotlin.Boolean
  //   Public signature: /Impl.contains|5952569342946134495[0]
  //   Public signature debug description: contains(kotlin.String?){}kotlin.Boolean
  override operator fun contains(element: String?): Boolean

  // CHECK JVM_IR:
  //   Mangled name: Impl#containsAll(kotlin.collections.Collection<kotlin.String?>){}kotlin.Boolean
  //   Public signature: /Impl.containsAll|1049727718390523309[0]
  //   Public signature debug description: containsAll(kotlin.collections.Collection<kotlin.String?>){}kotlin.Boolean
  override fun containsAll(elements: Collection<String?>): Boolean

  // CHECK JVM_IR:
  //   Mangled name: Impl#isEmpty(){}kotlin.Boolean
  //   Public signature: /Impl.isEmpty|-626562167393617703[0]
  //   Public signature debug description: isEmpty(){}kotlin.Boolean
  override fun isEmpty(): Boolean

  // CHECK JVM_IR:
  //   Mangled name: Impl#iterator(){}kotlin.collections.MutableIterator<kotlin.String?>
  //   Public signature: /Impl.iterator|-2471973611389785770[0]
  //   Public signature debug description: iterator(){}kotlin.collections.MutableIterator<kotlin.String?>
  override operator fun iterator(): MutableIterator<String?>

  // CHECK JVM_IR:
  //   Mangled name: Impl#remove(kotlin.String?){}kotlin.Boolean
  //   Public signature: /Impl.remove|8505628602427100346[0]
  //   Public signature debug description: remove(kotlin.String?){}kotlin.Boolean
  override fun remove(element: String?): Boolean

  // CHECK JVM_IR:
  //   Mangled name: Impl#removeAll(kotlin.collections.Collection<kotlin.String?>){}kotlin.Boolean
  //   Public signature: /Impl.removeAll|-7838912124890825774[0]
  //   Public signature debug description: removeAll(kotlin.collections.Collection<kotlin.String?>){}kotlin.Boolean
  override fun removeAll(elements: Collection<String?>): Boolean

  // CHECK JVM_IR:
  //   Mangled name: Impl#retainAll(kotlin.collections.Collection<kotlin.String?>){}kotlin.Boolean
  //   Public signature: /Impl.retainAll|6732730442391802777[0]
  //   Public signature debug description: retainAll(kotlin.collections.Collection<kotlin.String?>){}kotlin.Boolean
  override fun retainAll(elements: Collection<String?>): Boolean

  // CHECK:
  //   Mangled name: Impl{}size
  //   Public signature: /Impl.size|-6253659984320132064[0]
  //   Public signature debug description: {}size
  override val size: Int
    // CHECK JVM_IR:
    //   Mangled name: Impl#<get-size>(){}kotlin.Int
    //   Public signature: /Impl.size.<get-size>|-3941649985161900780[0]
    //   Public signature debug description: <get-size>(){}kotlin.Int
    override get(): Int

}

// CHECK JVM_IR:
//   Mangled name: #box(){}kotlin.String
//   Public signature: /box|-9347091776561469[0]
//   Public signature debug description: box(){}kotlin.String
fun box(): String