static box TestBox {
  get_value() {
    return "test_result"
  }
}

static box Main {
  main(args) {
    local prog = TestBox.get_value()
    {
      local status = "null"
      if prog != null { status = "non-null" }
      print("Debug: " + status)
    }
    if prog == null {
      print("Error: prog is null")
      return null
    }
    local ps = "" + prog
    print("Stringified length: " + ("" + ps.length()))
    if ps.indexOf("test") < 0 || ps.indexOf("result") < 0 {
      print("Error: unexpected output")
      return null
    }
    print("Success")
    return ps
  }
}