def foo(): () => Int = {
    var b = 11
    def goo() = {
      b = b + 23
      b
    }
    goo
  }                      //> foo: ()() => Int

  val a = foo()          //> a  : () => Int = <function0>
  a()                    //> res0: Int = 34
  a()            //> res1: Int = 57