using System;

public interface IFoo[S]
{ }

public class ArrayList[T]
{
  public virtual InsertAll (_ : IFoo[T]) :  int
  {
     0;
  }

        public virtual InsertAll[U] (_ : IFoo[U]) :  int
        {
     1;
        }

  public virtual AddAll (mutable  foo : IFoo[T]) :  int
  {
     InsertAll (foo);
  }
}

class X
{
  static Main () :  int
  {
    mutable  list_ =  ArrayList ();
     list_.AddAll (null);
  }
}
/*
BEGIN-OUTPUT
END-OUTPUT
*/