content: sub test1()
      print "ok"
      exec(sub()
          print "ok"
      end sub)
  end sub
  
  sub test2()
      print "ko"
      exec(sub()
          print "ko"
      end sub)
      return "ko"
  end sub
  
  sub test3()
      print "okko"
  end sub
  
  sub exec(x)
      return
      print "unreachable"
  end sub
  